Rose Lavelle scored in stoppage time and Gotham FC defeated the Portland Thorns 2-1 on Sunday to advance to the semifinals of the National Women's Soccer League playoffs.

Gotham, the defending NWSL champions, will face the second-seeded Washington Spirit next weekend. The Spirit defeated visiting Bay FC 2-1 in extra time earlier on Sunday in the quarterfinals.

It was the final NWSL game for Thorns forward Christine Sinclair of Burnaby, B.C., who is retiring after 12 seasons with the club.

A club record 15,540 fans were on hand for the match at Red Bull Arena. Gotham finished the season with the third seed, going 17-4-5.

The Thorns struggled down the stretch but defeated Angel City in the final regular season match to secure the eighth and final seed.

WATCH | Christine Sinclair leaves soccer pitch for final time:

Canadian icon Christine Sinclair leaves the soccer pitch for final time

Christine Sinclair was substituted off in her final game with the NWSL's Portland Thorns Sunday as they fell 2-1 to Gotham FC.

Sophia Smith, who played for the United States at the Olympics this summer, appeared to put the Thorns up in the 43rd minute but she was offside.

There was a lengthy video review in the second half to determine if Portland defender Becky Sauerbrunn committed a handball in the box, which would have given Gotham a penalty. Ultimately it wasn't ruled a penalty.

Tierna Davidson broke through with her first goal of the season to put Gotham up 1-0 in the 67th minute. It came off a free kick that Lavelle sent into a crowd in front of the goal.

Rookie Reilyn Turner's goal on a header off a set piece in the 75th minute pulled Portland even. Morgan Weaver nearly put the Thorns on top but her shot caromed off the post before Lavelle scored the winner seven minutes into stoppage time.

"It's always nice to score in stoppage time so you don't have to go into overtime," Lavelle said.

Sinclair, 41, has played for Portland since the NWSL's launch in 2013 and has helped the Thorns win NWSL championships in 2013, 2017 and 2022. She has scored a club-record 65 regular-season goals with the team, ranking third all-time in the league

Sinclair retired from the Canadian national team last year as international soccer's all-time leading scorer among both men and women with 190 goals.

Shield winners the Orlando Pride, the top seed, will face the Kansas City Current next weekend in the other semifinal. The NWSL championship will be played on Nov. 23 at Kansas City's CPKC Stadium.