Tennis's biggest names have hit highs and lows down under over the weekend, with stars like Coco Gauff seeing mixed results at the 2026 United Cup as the annual Australian Open team tune-up tournament heads into its knockout rounds.
World No. 4 Coco Gauff and the reigning champion Team USA are through to the quarterfinals, joined by top WTA competitor and No. 11 Belinda Bencic of Team Switzerland.
Argentina, Australia, Belgium, Czechia, and Greece also punched their tickets to the knockouts, with Tuesday night's final group-stage bout deciding whether No. 2 Iga Świątek and Team Poland or Team Germany will claim the final spot in the quarterfinals.
Thus far in the team competition, however, Gauff has experienced a particularly up-and-down tournament, suffering her first-ever United Cup singles defeat on Monday against No. 42 Jessica Bouzas Maneiro of Spain after causing a stir with her postmatch comments.
"I feel like we're definitely, in tennis, the worst," she told reporters before the singles showdown. "I've always said I wish our country in other places would show up throughout the world as we see smaller countries support."
After taking some heat, the 21-year-old later clarified her position on social media, writing "Trust me I understand the financial aspect of things and know tennis is not accessible for everyone, it was more of a comment for those who are already attending and how I wish they were as passionate as those from other countries."
How to watch Gauff and Team USA at the 2026 United Cup
Gauff will look to return to form against No. 51 Maria Sakkari when Team USA kicks off the 2026 United Cup quarterfinals against Team Greece at 9 PM ET on Tuesday, airing live on the Tennis Channel.
The world's tennis stars are preparing to open 2026 play in Australia this weekend, with top WTA and ATP leaders on Team USA gearing up to defend their United Cup title starting this Friday.
The two-time champion US enters as the No. 1 seed in the fourth edition of the hard-court tournament, bolstered by the return of world No. 3 Coco Gauff to lead Team USA's six-player United Cup contingent.
With each tournament bout consisting of one WTA singles match, one ATP singles clash, and one mixed-doubles competition, Gauff notably claimed a straight-sets victory over Polish phenom No. 2 Iga Świątek to secure the 2025 title for the US.
"I'm super excited," the 21-year-old star said prior to this year's United Cup. "I had such a good time in my first year playing with the team, and I'm looking forward to going back."
With the 2026 Australian Open beginning in less than two weeks, the United Cup pits 18 national teams against each other as players from both the women's and men's tours tune up for next year's Slams.
Fellow WTA Top-10 stars Świątek and Italy's No. 8 Jasmine Paolini will join Gauff on the 2026 United Cup court, while fan favorite No. 16 Naomi Osaka will feature for tournament debutant Japan.
Also battling for national pride will be two winners of last season's WTA awards, with 2025 Newcomer of the Year No. 18 Vicky Mboko joining Team Canada and 2025 Comeback Player of the Year No. 11 Belinda Bencic competing for Switzerland.
How to watch the 2026 United Cup
The 2026 United Cup runs January 2nd through 11th, with live coverage airing on the Tennis Channel.
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.
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.
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.