US tennis player Madison Keys earned her first-ever Grand Slam title on Saturday, taking down back-to-back defending champ and world No. 1 Aryna Sabalenka in the 2025 Australian Open final.

On the heels of a three-set semifinal ousting of No. 2 Iga Świątek last Thursday, Keys' 6-3, 2-6, 7-5 Saturday victory made her the first player to upset both the world No. 1 and No. 2 in the same Grand Slam since Svetlana Kuznetsova did so at the 2009 French Open. The 29-year-old is also the first to do it in Melbourne since Serena Williams in 2005.

Only three other WTA players have racked up more Grand Slam main draws before winning their first title. On Saturday, Keys tied Caroline Wozniacki for making the most Australian Open main-draw singles appearances before lifting the trophy.

Keys's Australian Open run included five wins over seeded opponents, four of them in the WTA's Top 10 entering the tournament. Plus, with five three-set victories, Keys tied the record for the most three-set wins at any of the four Grand Slams.

However, none of those records compare with winning her first major.

"I’ve wanted this for so long," Keys said holding her trophy during the post-match ceremony.

View this post on Instagram

A post shared by Just Women’s Sports (@justwomenssports)

Keys' championship was years in the making

Keys burst onto the pro scene on her 14th birthday back in 2009, and has been a Top 20 mainstay for most of the last decade.

The US star has appeared in at least the quarterfinal round of all four majors multiple times. However, she had only one Grand Slam final under her belt prior to this weekend's championship match — a 2017 US Open loss to Sloane Stephens.

Ultimately, it took relinquishing her desperation to win a Slam to actually snag that elusive trophy.

"I've done a lot of work to no longer need [winning a Grand Slam]," Keys explained after her win. "I really wanted it, but it's no longer the thing that was going to define me, and kind of letting go of that burden, I finally gave myself the ability to play for it."

2025 Australian Open runner-up Aryna Sabalenka smiles at champion Madison Keys while holding their hardware.
With her Grand Slam title, Keys joins No. 1 Sabalenka in the WTA Top 10. (Mark Avellino/Anadolu via Getty Images)

Slam win returns Keys to the WTA's Top 10

The WTA updated their rankings early Monday, with Keys's breakthrough performance boosting her to No. 7 — her first Top 10 slot since January 2023. The new rank also ties her career-high, with Keys first peaking at No. 7 in October 2016.

Keys's rise also solidifies the US as arguably the nation most flush with the sport's top talent. The US now boasts four players in the Top 10, with Keys joining No. 3 Coco Gauff, No. 6 Jessica Pegula, and No. 9 Emma Navarro. No other nation has more than one athlete in that elite tier.

That said, the WTA's best stayed put in Monday's rankings. Despite their Australian Open losses, all four top seeds — Sabalenka, Świątek, Gauff, and No. 4 Jasmine Paolini — retained their top spots.

In the biggest upset of the 2025 Australian Open so far, 19-seed Madison Keys defeated world No. 2 Iga Świątek in a back-and-forth three-set semifinal early Thursday morning.

Entering as the tournament's only athlete to win every set, five-time Grand Slam champion Świątek conceded more games to Keys than in her previous five Australian Open matches combined.

Keys's speedy serve and heavy forehand paired with a Świątek double-fault pushed the match to a tie-break decider, with the US star ultimately winning 5-7, 6-1, 7-6 (10-8).

"It just became who can get that final point and who can be a little bit better than the other one," Keys said post-match. "I'm happy it was me."

View this post on Instagram

A post shared by Just Women’s Sports (@justwomenssports)

Keys's victory is just the latest chapter in a 2025 Australian Open run that's seen her beat three Top 10 contenders in Świątek, No. 6 Elena Rybakina, and No. 10 Danielle Collins. Those victories earned the 29-year-old her own Top 10 spot in next Monday’s WTA rankings.

With Thursday's win, Keys booked her second-ever Grand Slam championship match, returning to the sport's top stage for the first time since the 2017 US Open.

Aryna Sabalenka backhands a shot during her 2025 Australian Open semifinal.
Keys must defeat reigning champion Sabalenka to earn her first Slam title on Saturday. (Shi Tang/Getty Images)

One last challenge awaits Keys

To claim her career's first Grand Slam trophy, however, Keys will have to defeat reigning champion and world No. 1 Aryna Sabalenka, who comfortably downed Spain's No. 11 Paula Badosa 6-4, 6-2 on Thursday in pursuit of a third-straight Australian Open title.

In their five previous meetings, Keys has only beaten Sabalenka once, topping her in Berlin in 2021.

Sabalenka won their most recent bout in the 2023 US Open semifinals. However, that three-set slog was similar to Keys's gritty victory over Świątek and, if she can maintain the composure and energy she displayed on Thursday, the US star's momentum could fuel her to similarly stun Sabalenka.

Aryna Sabalenka plays a backhand in the Women's Singles Semi Finals match against Paula Badosa of Spain during day twelve of the 2025 Australian Open at Melbourne Park on January 23, 2025 in Melbourne, Australia.
Keys will play defending Australian Open winner Aryna Sabalenka in the tournament's final. (Shi Tang/Getty Images)

How to watch the 2025 Australian Open final

Saturday's Australian Open final between Keys and Sabalenka will take the court at 3:30 AM ET, with live coverage on ESPN.

World No. 3 Coco Gauff exited the 2025 Australian Open on Monday night, falling 7-5, 6-4 to Spain's No. 11 Paula Badosa in the Grand Slam's quarterfinal round.

Gauff's recent improvements seemed to fade in her first loss of the year, which saw the 2025 United Cup champ record 41 unforced errors, including 28 missed forehands and six double-faults.

As a result, Badosa advances to her first-ever Grand Slam semifinal, a marked comeback after a 2023 injury nearly ended her career.

"I would never think that, a year after, I would be here," Badosa said post-match. "I've been through a lot."

Aryna Sabalenka sets up a forehand during her 2025 Australian Open quarterfinal.
Sabalenka's 25-set Australian Open win streak was snapped on Tuesday. (Jason Heidrich/Icon Sportswire via Getty Images)

Sabalenka looms after quarterfinal victory

Badosa moves on to face back-to-back defending champion Aryna Sabalenka on Thursday, as the world No. 1 sets her sights on becoming the first three-peat Australian Open women's champ this century.

Sabalenka advanced past No. 27 Anastasia Pavlyuchenkova in an early Tuesday morning quarterfinal to reach her 10th major semifinal in her last 11 Grand Slams.

The 6-2, 2-6, 6-3 victory didn't come easily, though, as Pavlyuchenkova managed to snap the 26-year-old's 25-set Australian Open winning streak which dates back to her 2023 final win.

"I’m really glad that at some point I was able to put myself back together," said Sabalenka about the tough match. "I was able to keep fighting, keep trying, and I was able to turn around this match. It was a really difficult one."

Madison Keys celebrates a point at the 2025 Australian Open.
No. 19 Madison Keys has emphatically ousted two Top-10 contenders at the 2025 Australian Open. (Daniel Pockett/Getty Images)

US players to close out Australian Open quarterfinals

The Melbourne Slam's remaining two quarterfinals each place a US tennis star in the spotlight on Tuesday.

Fresh off ousting No. 10 Danielle Collins and No. 6 Elena Rybakina in the third and fourth rounds, No. 19 Madison Keys will square off against No. 28 Elina Svitolina for a shot at the semis. This will be Keys's first match against the Ukrainian since taking a two-set victory over Svitolina in Adelaide in January 2022.

The nightcap pits three-set specialist No. 8 Emma Navarro against perennial contender No. 2 Iga Świątek, marking the second-ever meeting — and first since 2018 — between the 23-year-olds.

The Polish phenom has yet to drop a set all tournament, and has seemed near-unbeatable after losing just four games across her last three matches. That said, Navarro has proved she just won't quit, leading the WTA in three-set contests over the last year — and gritting out a 24-9 record in the same span. Consequently, the longer Tuesday's match runs, the more it will likely favor the US star.

How to watch the 2025 Australian Open this week

No. 19 Madison Keys will clash with No. 28 Elina Svitolina starting at 7:30 PM ET on Tuesday, with No. 8 Emma Navarro's bout against No. 2 Iga Świątek beginning at 9 PM ET.

Both Tuesday quarterfinals will be broadcast live across ESPN’s platforms.

Tennis's first Grand Slam of 2025 kicks off on Saturday, with the sport's heaviest hitters convening in Melbourne for the Australian Open.

World No. 1 Aryna Sabalenka — the reigning back-to-back Australian Open champion — enters as the tournament's first overall seed for the first time. However, she'll see stiff competition by way of No. 2 Iga Świątek, No. 3 Coco Gauff, and No. 4 Jasmine Paolini.

"For me being the one to chase... I like that feeling," Sabalenka told reporters this morning. "That's what drives me and helps me to stay motivated because I know that I have a target on my back."

No. 3 Coco Gauff sets up a forehand during her United Cup match against No. 2 Iga Świątek.
Coco Gauff's 2025 Australia Open path includes Naomi Osaka and Jessica Pegula. (Robert Prange/Getty Images)

Tough roads to the trophy litter Australian Open draw

Each top contender faces a tricky tournament draw, with upset potential lurking in every quadrant.

Sabalenka could meet 2024 Olympic gold medalist and WTA Finals runner-up No. 5 Zheng Qinwen as early as the quarterfinals, as long as she survives a first-round matchup against 2017 US Open winner Sloane Stephens.

Reigning WTA Finals champion Gauff's quadrant is in Sabalenka's half of the field, setting up a possible rematch of last year's semifinal. As for the 20-year-old US star's path, earlier rounds could see Gauff contending with tough competitors like 2021 Australian Open champ Naomi Osaka, 2024 US Open semifinalist Karolína Muchová, and 2024 US Open finalist No. 7 Jessica Pegula.

Świątek and Paolini could also meet in a semifinal, though fellow top competitors No. 8 Emma Navarro and 2020 Australian Open winner Ons Jabeur stand in Świątek's way while No. 10 Danielle Collins and 2022 Wimbledon champion No. 6 Elena Rybakina have been drawn into Paolini's quadrant.

How to watch the 2025 Australian Open

The 2025 Australian Open's first round starts on Saturday at 7 PM ET, with Sabalenka's first-round match set for 3 AM ET on Sunday.

Live coverage for the tournament will air across ESPN platforms.

World No. 3 Coco Gauff took down No. 2 Iga Świątek in straight sets at Sunday's United Cup final, helping to secure a big US team win at the Australian Open tune-up tournament.

"It's great to win a team event, the only team event I've ever won, so I'm super excited," Gauff said after the match.

With Sunday's victory, Team USA owns two of the three titles in the annual 18-country contest, adding the 2025 trophy to their inaugural 2023 hardware. Świątek's Poland, on the other hand, fell short for the second year in a row after also earning runner-up status behind 2024 champion Germany.

Tennis star Coco Gauff leaps in celebration over a point against Iga Świątek in the United Cup final.
Gauff has won her last two matches against Iga Świątek. (Andy Cheung/Getty Images)

Gauff doesn't skip a beat in 2025 kickoff

After winning every set in the new year, Gauff remains undefeated in 2025 play, maintaining the momentum she built by closing out her 2024 campaign with victories at both October's China Open and November's WTA Finals.

The 20-year-old faltered in her attempt to defend her 2023 US Open title, falling in the fourth round of the Grand Slam's 2024 edition last September. In the wake of that disappointing result, Gauff parted ways with coach Brad Gilbert, and began tweaking her game to solidify her style — with a particular focus on grip strength.

Behind new coach Matt Daly, the changes to Gauff's grip improved both her serve and her forehand — the latter something Świątek had exploited to consistent success over Gauff, with the Polish star logging 11 wins in the pair's first 12 meetings.

The era of Świątek's dominance over Gauff seems to have ended, however, with the US phenom now adding two straight wins over Świątek to the pair's all-time tally, tacking Sunday's victory on top of their 2024 WTA Finals tilt — a tournament in which Gauff also defeated world No. 1 Aryna Sabalenka.

Her trend of downing top-ranked international tennis stars continued at the United Cup, where Gauff also defeated No. 31 Leylah Fernandez, No. 19 Donna Vekic, and 2024 US Open semifinalist No. 21 Karolina Muchová en route to the US team title.

"I have the belief that I'm one of the best players in the world. When I play good tennis, I'm hard to beat," Gauff added on Sunday.

Tennis stars Aryna Sabalenka and Coco Gauff pose by the net before their 2024 WTA Finals match.
Gauff will try to spoil Sabalenka's three-peat attempt at the 2025 Australian Open. (Artur Widak/NurPhoto via Getty Images)

First 2025 Slam to test Gauff's momentum

Gauff's hot streak will face its first major 2025 challenge when tennis' first Grand Slam of the year, the Australian Open, kicks off on January 12th to run through January 25th.

The Melbourne tournament will see Sabalenka, who opened her 2025 account with an 18th career title at the Brisbane International on Sunday, try to become the first three-peat Australian Open women's champion this century.

However, Gauff is primed to interrupt that feat, with the US star poised to give the back-to-back defending champ a run for her money.

World No. 3 tennis star Coco Gauff won the 2024 WTA Finals on Saturday, becoming the youngest US player to take the tournament since Serena Williams in 2001.

Gauff's championship came by way of a grueling three-hour 3-6, 6-4, 7-6 (2) final match win over reigning Olympic champion Zheng Qinwen.

The 20-year-old's road to the $4.8 million purse — the largest in women's tennis history — included just her second-ever win over No. 2 Iga Świątek in the group round and a semifinal victory over No. 1 Aryna Sabalenka on Friday.

View this post on Instagram

A post shared by Just Women’s Sports (@justwomenssports)

A winning end to a rollercoaster season

When asked about her 2024 season, Gauff told reporters, "There’s been a lot of ups and downs. At moments, it felt great. At other moments, it felt awful. Basically, a typical year on tour."

Her low point was a disappointing attempt to defend her 2023 US Open title. Gauff stumbled out of the US Grand Slam in the fourth round this fall.

That performance led Gauff to an apparently productive coaching change. She left coach Brad Gilbert, adding Matt Daly to her team to work with Jean-Christophe “JC” Faurel.

Since then, Gauff has gone 13-2, ultimately adding the China Open and WTA Finals titles to her June French Open doubles trophy.

After silencing doubters with Saturday's victory, Gauff took to social media, writing "lol safe to say I beat the bad season allegations."

New Zealand's Erin Routliffe and Canada's Gabriela Dabrowski lift their 2024 WTA Finals doubles trophy.
Erin Routliffe and Gabriela Dabrowski paired up to make WTA Finals history. (Matthew Stockman/Getty Images for WTA)

A double dose of WTA Finals history

Just before Gauff took the court, Canadian Gabriela Dabrowski and New Zealand's Erin Routliffe were crowned the season's doubles champions.

Dabrowski and Routliffe avenged their Wimbledon final loss by defeating US player Taylor Townsend and her Czech partner Kateřina Siniaková 7-5, 6-3 on Saturday. They are now the first athletes from Canada and New Zealand to win the WTA Finals doubles title.

For only the second time in 13 career tries, 20-year-old US tennis star Coco Gauff defeated former World No. 1 Iga Świątek in straight sets at the 2024 WTA Finals on Tuesday, guaranteeing Gauff a spot in Saturday's semifinals.

No. 3 Gauff clinched the 6-3, 6-4 result in one hour and 48 minutes on Riyadh’s Center Court to join Aryna Sabalenka as the first two players to book tickets to the semifinals.

"I knew going into the match, despite our head-to-head [history], I had a lot of confidence and I felt like I was playing great tennis," Gauff said after the match.

The first and only other time Gauff defeated Świątek was at the 2023 Cincinnati Open, when the pair battled to a 7-6(2), 3-6, 6-4 finish. Gauff went on to win that tournament, just weeks before earning her first Grand Slam championship by winning the 2023 US Open.

Gauff's Tuesday win also guarantees that Sabalenka will finish the calendar year as World No. 1, bolstered by her 2024 US Open win and her strong performances this week.

World No. 1 Aryna Sabalenka tosses a serve at the 2024 WTA Finals.
Despite falling to Elena Rybakina on Wednesday, Aryna Sabalenka advanced to the WTA Finals semis. (Robert Prange/Getty Images)

Semifinals take shape

While Sabalenka and No. 7 Qinwen Zheng both advanced from the Purple Group on Wednesday, ending No. 4 Jasmine Paolini's and No. 5 Elena Rybakina's WTA Finals runs, Gauff and Świątek each have one more group match on the tournament's docket.

Gauff will aim to win the Orange Group outright by defeating No. 8 Barbora Krejčíková on Thursday. As for Krejčíková, she'll be competing for a shot at advancing over Świątek, who will look to defeat alternate Daria Kasatkina to claim the final semifinals spot.

No. 6 Jessica Pegula walks away on the 2024 WTA Finals court.
US star Jessica Pegula's ongoing knee injury forced her to withdraw from the WTA Finals. (Artur Widak/NurPhoto via Getty Images)

Pegula withdraws with injury

Kasatkina is stepping in at the eleventh hour after Gauff's compatriot, No. 6 Jessica Pegula, withdrew from the competition with a left knee injury on Wednesday.

The 30-year-old Pegula, who was already eliminated from advancing after falling 6-3, 6-3 to Krejčíková on Tuesday, has nursed the injury since before the WTA Finals began.

"What started as a really small issue flared over the last two matches and I just can’t continue tomorrow," Pegula tweeted. "I’m sorry to the fans and tournament. I really had a great week of prep and had high hopes here but it just wasn’t meant to be."

How to watch Coco Gauff at Thursday's WTA Finals

Świątek and Kasatkina will kick off the final group-stage day at the 2024 WTA Finals at 7:30 AM ET, with Gauff taking on Krejčíková at 10 AM ET. Both matches will air live on the Tennis Channel.

The year's final major tennis tournament begins on Saturday when the sport's highest-ranked athletes descend on Riyadh, Saudi Arabia to compete in the 2024 WTA Finals.

Featuring the eight best singles players and eight best doubles teams, Slam winners and Olympic medalists alike will compete for the Billie Jean King and Martina Navratilova trophies before the winter break.

Also up for grabs is a piece of the record $15.25 million prize pool, larger than any Grand Slam purse and a nearly 70% increase over the 2023 pot. Should the champions go undefeated through the tournament, the singles winner will bank $5.155 million, while the top doubles duo will take home $1.125 million.

WTA tennis stars Coco Gauff and Jessica Pegula play doubles together at Wimbledon 2024.
2024 French Open and Wimbledon doubles teammates Coco Gauff and Jessica Pegula will open their WTA Finals singles campaigns against each other. (Francois Nel/Getty Images)

Eight days of elite tennis action

In both the WTA Finals singles and doubles categories, competitors are split into two groups of four.

Each singles player or doubles pair will play all others in their group for a total of three matches across the first six days. The top two in each group will then compete in the November 8th semifinals, with both finals set for November 9th.

In the singles contest, the Purple Group includes No. 1 Aryna Sabalenka, No. 4 Jasmine Paolini, No. 5 Elena Rybakina, and No. 7 Qinwen Zheng, while the Orange Group lists No. 2 Iga Świątek, No. 3 Coco Gauff, No. 6 Jessica Pegula, and No. 8 Barbora Krejčíková.

In both competitions, 25% of the top eight athletes represent the USA. Along with Gauff and Pegula on the singles court, the doubles tournament includes No. 5 US duo Caroline Dolehide and Desirae Krawczyk as well as Nicole Melichar-Martinez and Taylor Townsend in the Nos. 6 and 8 pairs, respectively.

World No. 1 tennis player Aryna Sabalenka and No. 2 Iga Świątek share a friendly moment during practice for the 2024 WTA Finals.
Off-court friends No. 1 Aryana Sabalenka and No. 2 Iga Świątek are fierce on-court competitors. (Robert Prange/Getty Images)

Will Sabalenka play Świątek at the WTA Finals?

A showdown between Sabalenka and 2023 WTA Finals champion Świątek could be the event's blockbuster match. The top-ranked players have yet to square off in a major tournament in 2024 — a year rife with highs and lows for both athletes.

Sabalenka started the WTA season by winning her second Australian Open, then later struggled through a shoulder injury that forced her to withdraw from Wimbledon. She capped the Grand Slam season in style, though, winning her first US Open in September.

As for five-time Grand Slam victor Świątek, 2024 brought the Polish phenom her fourth French Open title. A rockier second half to the season — including a third round and quarterfinal ousting from Wimbledon and the US Open, and a fall from the No. 1 ranking for the first time since November 2023 — motivated Świątek to seek a new coach.

How to watch the 2024 WTA Finals tennis tournament

The 2024 WTA Finals kicks off on Saturday, when US Open winner Sabalenka plays 2024 Olympic gold medalist Zheng at 11 AM ET.

Later, 2023 US Open champ Gauff will take on 2024 US Open runner-up Pegula at 8:45 AM ET on Sunday.

All 2024 WTA Finals matches will be broadcast live on the Tennis Channel.

For the second year in a row, there will be a US tennis player facing Aryna Sabalenka in the final of the US Open, after Jessica Pegula wrapped up the best week of her career.

Having reached the quarterfinals in all four major tournaments, Pegula finally broke through to her first Slam semifinal and then final this week with wins over Iga Swiatek and Karolina Muchova.

A career-best run

Currently ranked No. 6 in the world, Pegula has played some of the best tennis of her career recently, reaching the quarterfinal of the Australian Open in 2021-23, and the quarterfinal of the French Open in 2022, and the US Open in 2023.

But Wednesday's straight-set win over World No. 1 Swiatek proved to be her first time breaking 'the quarterfinal curse,' with the hope of carrying the momentum all the way to the final.

Pegula had to battle back from a slow first set in her semifinal on Thursday, as Muchova took an early 6-1 lead and then a 3-0 advantage in the second set.

"I came out flat, but she was playing unbelievable," Pegula said after the match. "She made me look like a beginner. I was about to burst into tears because it was embarrassing. She was destroying me." But the 30-year-old battled back to take the second set 6-4 and rolled to a 6-2 win in the deciding third set, continuing her impressive 15-1 record since the Paris Olympics.

"I was able to find a way, find some adrenaline, find my legs," Pegula said. "At the end of the second set into the third set, I started to play how I wanted to play. It took a while but I don't know how I turned that around honestly."

View this post on Instagram

A post shared by US Open (@usopen)

Finishing the job

Pegula will face World No. 2 Aryna Sabalenka, who defeated her in Cincinnati, and who advanced past Emma Navarro in straight sets on Thursday. Sabalenka has only dropped one set this US Open, after not participating in the Olympics. The Belarusian will be looking for her second-ever Grand Slam title after coming up just short against Coco Gauff in New York in 2023.

View this post on Instagram

A post shared by US Open (@usopen)

"Hopefully I can get some revenge out here," said Pegula.

In her first-ever Grand Slam quarterfinal victory, No. 6-seed Jessica Pegula knocked No. 1 Iga Świątek out of the 2024 US Open in straight sets Wednesday night.

Now in uncharted territory, the US tennis star will aim at extending her historic run in tonight's semifinal against unseeded Czech opponent, Karolina Muchová.

View this post on Instagram

A post shared by Just Women’s Sports (@justwomenssports)

Quarterfinal victory proved Pegula's dominance

The 30-year-old Pegula, who has yet to drop a set all tournament, took control of yesterday's match immediately, winning the first game on Świątek's serve — the five-time Grand Slam winner's first broken serve in 26 games.

Świątek, the 2022 US Open champion, committed 18 unforced errors in the first set. Visibly frustrated with her performance, the Polish phenom retreated to the locker room to regroup — a move that ultimately proved unsuccessful in the wake of Pegula's relentless 6-2, 6-4 victory.

After six previous Grand Slam quarterfinal attempts, Pegula celebrated, telling the crowd post-match that "there have been so many freaking times, and I just kept losing.... So thank God I was able to do it. And finally — finally! — I can say, 'Semifinalist.'"

US tennis player Emma Navarro hits the ball in her 2024 US Open quarterfinal win
No. 13 Emma Navarro joins No. 6 Jessica Pegula as the two US players to make the 2024 US Open semis. (Robert Prange/Getty Images)

Two US contenders will feature in tonight's semis

Pegula isn't the only contender making her Grand Slam semifinal debut tonight. Before Pegula takes the court, fellow US player No. 13 Emma Navarro will take on reigning back-to-back Australian Open champion No. 2 Aryna Sabalenka.

Sabalenka, who fell to US star Coco Gauff in last year's US Open, hopes for better luck against Navarro — the player who ousted the No. 3 defending champ last weekend.

If both Pegula and Navarro emerge victorious, Saturday's US Open final would be the first contested by two US athletes since Sloane Stephens defeated Madison Keys for the 2017 title. It would also pit two New York locals against each other on their home Grand Slam court: Pegula hails from Buffalo, NY, while Navarro was born in NYC.

How to watch the 2024 US Open semifinals

Navarro and Sabalenka will kick off tonight's Grand Slam action at 7 PM ET, with Pegula's match against Muchová immediately following. Both semis will air on ESPN.