Claire Emslie scored the game-winner against San Diego in her debut for Angel City. (Jayne Kamin-Oncea/USA TODAY Sports)

LOS ANGELES — Fans had the inaugural NWSL regular-season match between Angel City FC and San Diego Wave circled on their calendars for months. The expansion clubs would not only be playing for bragging rights in their debut seasons, but Angel City — the league leader in average attendance — would have another opportunity to showcase its growing fan base.

With the new rivals playing in front of a sellout crowd of 22,000 at Banc of California Stadium on Saturday night, the game’s drama matched its anticipation. Angel City, despite going a player down late in the second half, defeated the first-place Wave 2-1 to tie the Portland Thorns with 17 total points in the league standings.

ACFC captain Ali Riley, the game’s first goal scorer, saw Saturday’s game as a celebration of the progress this country has made with women’s soccer and women’s sports, and she expects the rivalry with San Diego to propel the NWSL further.

“I thought all day about how incredible it is to not just have one team in Southern California, but to now have two,” Riley said after the inaugural Chanclásico (chanclas is the Spanish word for flip flops). “We haven’t had that before, and it’s not something I was able to see when I was growing up.”

ACFC president Julie Uhrman also spoke about the budding rivalry.

“This is a city of champions, and we want to be the best in the league, but we absolutely want to be the best in Southern California,” she said. “As much appreciation as I have for San Diego and as much as I want them to be successful this year, every single time we step on the pitch, we’re looking for the three points and the rivalry makes it a bigger game.”

In the 81st minute, as Angel City was playing with just 10 players after Tyler Lussi received her second yellow card of the match, a wide-open Claire Emslie scored from the right side of the box off a cross from Cari Roccaro. The right-footed shot to the bottom left corner gave the home team a 2-1 lead it would not squander. It was also ACFC’s first score in front of its supporters’ section all season.

Emslie, a 28-year-old forward from Scotland, made her team debut off the bench after landing in Los Angeles on Tuesday and officially signing on Thursday. For dinner the night before the match, Riley made Emslie vegan enchiladas to welcome her. The jetlagged Emslie, who was the organization’s second pick in the expansion draft, has been drinking coffee at night to stay awake. She said she has been so exhausted that she has begun feeling tired around 6 p.m. since landing in L.A.

In the ninth minute of the match, Riley drilled the opening goal with a left-footed strike through a tight window past San Diego goalkeeper Carly Telford. Jun Endo made the assist on a setup from Sydney Leroux. The goal marked the 34-year-old defender’s first in the 2,155th minute and 29th game of her NWSL career. Emslie’s goal was also the first of her NWSL career.

Leroux, who spent her college years across town at UCLA, was listed as questionable for the game with a right ankle injury. Making her first start for ACFC a week after debuting with the team following a trade from the Orlando Pride, Leroux didn’t take long to assuage concerns over her health.

In the second minute of the second half, Leroux nearly doubled her team’s lead with a nifty bicycle kick that went wide right. Five minutes later, when it appeared Leroux had scored on another attempt, the crowd erupted and pink smoke emanated from the supporters’ section. The noise died down when the forward was ruled offside and the goal was disallowed.

ACFC keeper DiDi Haračić was spectacular throughout the match, and especially busy in the closing moments. In the 86th minute, the goalie flashed the save of the match, jumping to deflect an on-target header out of play. Three minutes later, San Diego missed a go-ahead goal by inches on a Katie Johnson attempt from close range.

Kristen McNabb scored the Wave’s lone goal in the 60th minute, evening up the match with a left-footed drive into the bottom left corner. The Wave dominated possession in the first half (58.5 percent) and in the contest overall (56.2). They also outshot their northern neighbors 18 to nine, completed 27 crosses compared to ACFC’s eight and kicked five more corners than their opponent. And yet, the home club found a path to victory.

Important players on both sides missed the contest in favor of Women’s World Cup Qualifiers, including the league’s leading goal scorer, San Diego forward Alex Morgan (U.S.). For ACFC, starting defenders Vanessa Gilles (Canada) and Alyson Swaby (Jamaica) were also sidelined due to international duty. The club continues to be without star striker Christen Press and key defenders Jasmyne Spencer and Sarah Gorden due to injury. Press was met with enthusiastic pregame applause when she was shown on the jumbotron walking with crutches, flanked by ACFC investors Jennifer Garner and Glennon Doyle.

As ACFC players and staff reflected on their second sellout of the season Saturday night, they were equally proud and emphatic about the future. The Los Angeles club continues to easily pace the league in average attendance, with 19,006 fans per its seven home contests.

“Invest in us,” Riley said. “Look at all the people who care about women’s soccer, not just in Southern California.”

“We’re trying to show that women’s sports deserve the attention that these women got tonight,” Uhrman added. “The fans have supported this team in a way that feels completely unrivaled in women’s sports. You’re starting to see us women believing in our power and our strength and saying enough is enough, we deserve the attention.”

Joshua Fischman is a contributing writer at Just Women’s Sports covering Angel City FC and the Los Angeles Sparks. He has covered basketball for Vantage Sports and Hoops Rumors and served as co-host of “On the NBA Beat” podcast. Joshua received his master’s in Sports Media from Northwestern University’s Medill School of Journalism. Follow him on Twitter @JJTheJuggernaut.