Coco Gauff came from behind to beat Marta Kostyuk 6-4, 7-5 in Group 1 of the WTA Finals in Indian Wells, California, on Thursday, keeping alive her hopes of reaching the semi-finals of the elite season-ending event. The world No 4 trailed 5-1 in the second set, saved three set points in the seventh game and then won six straight games to close out the match in one hour and 39 minutes, despite nine double faults.

The first set was a contest of its own. Gauff was broken in the opening game but broke back, then broke Kostyuk again to lead 4-2 and held for 5-2. Kostyuk took a medical timeout for treatment on her right wrist, had it taped and broke Gauff as the American served for the set. Gauff regained control to take the set 6-4. The second set turned sharply: Kostyuk raced to a 3-0 lead, Gauff called for the trainer for treatment on her lower back, which she said was stiff and bothered her mostly on serve, and Kostyuk moved to 5-1 ahead. From there Gauff broke back for 5-3, won eight points in a row to level at 5-5 and broke again to seal the win.S1S2

The result leaves Gauff dependent on other results. Linda Noskova, the Wimbledon champion, has already qualified for the semi-finals. If Jessica Pegula beats Noskova in the final group match on Thursday, Pegula advances instead. If Noskova wins, Gauff goes through as group runner-up. If Pegula wins, the three players will be tied at 2-1 and Pegula will take second place on percentage of sets won. Gauff leads her head-to-head with Kostyuk 5-2, while Kostyuk, a late call-up who replaced defending champion Elena Rybakina, ends her week without a win and has lost seven matches in a row. Gauff, the 2024 champion, is chasing her third semi-final at the WTA Finals, which are scheduled for Saturday.S1S2