Coco Gauff was down 5-1. She won the last six games and kept her season alive.

Coco Gauff was a game from losing the second set, and with it her place at the WTA Finals. Then she won six games in a row.

The 22-year-old beat Marta Kostyuk 6-4, 7-5 on Thursday in Indian Wells, California, after trailing 5-1 in the second set. A trainer treated her for back trouble during the match. She closed it out anyway, and her semifinal hopes are alive.

She does not control what comes next. Linda Noskova, the Wimbledon champion, has already clinched a semifinal spot. Gauff goes through if Jessica Pegula loses to Noskova. If Pegula wins, Pegula and Noskova advance and Gauff is out. It is an odd spot for a player who beat Pegula, her fellow American, in three sets in her opening group match.

“One game turned into another and I think she got a little bit frustrated too, so that kind of helped me,” Gauff said of the comeback.

Kostyuk entered the event as the first alternate after top-ranked Elena Rybakina withdrew with a viral illness, and she finished group play without a win. The tournament was moved to Southern California from Saudi Arabia because of the Iran war.

Gauff won this event in 2024. She plays it as one of the most visible Black athletes in a sport that did not let Althea Gibson into its national championships until 1950, and she is still carrying that history into rooms where few players look like her. Down 5-1 with a sore back is as plain a test of that as there is, and she passed it.

Her season now turns on the match between Pegula and Noskova. If Pegula loses, Gauff plays on in the semifinals.