Coco Gauff Defeats Marta Kostyuk at WTA Finals Despite Back Pain

Coco Gauff kept her tournament hopes alive on Thursday at the WTA Finals, overcoming back pain and a erratic start to defeat Marta Kostyuk 6-4, 7-5 in a strange round-robin encounter.

The 22-year-old American looked in control early, racing to a 5-2 lead in the opening set before her momentum evaporated. Kostyuk, who entered the eight-player field as an alternate following world number one Elena Rybakina’s withdrawal due to a viral infection, clawed back to 5-4.

But serving to equalize, the Ukrainian player made a string of poor choices, allowing Gauff to clinch the opening frame in just under 50 minutes, La Presse reported.

Things deteriorated quickly for the Atlanta native in the second set as severe back pain took hold. Gauff leaked a double break and called for a medical timeout while trailing 3-0, visibly diminished and struggling with her serve. Yet she somehow found a foothold, holding serve for 4-1 before embarking on a six-game tear that turned the match on its head, according to RDS.

“Je sais que je peux me qualifier en fonction des différents scénarios possibles, et qu’ils ont tous été expliqués, mais je trouve toute cette histoire un peu absurde,” Gauff told reporters, criticizing the round-robin format as reported by ski-nordique.net.

Having saved three set points when trailing 5-2 in the second set, Gauff rediscovered her depth and court coverage to subdue Kostyuk’s erratic firepower. The victory leaves the fourth-ranked American with a 1-1 record in group play, though her path to the semifinals depended entirely on the late-night clash between compatriot Jessica Pegula and already-qualified Czech player Linda Noskova.

Noskova booked her spot in the semifinals on Tuesday by dismissing Gauff in straight sets, Radio-Canada reported. The 21-year-old Wimbledon champion notched a 6-3, 6-3 victory over Gauff in 75 minutes, using nine aces and four early breaks in the opening set to control the tempo.

Beyond her physical struggles on the court, Gauff used her press conference to voice deep frustration with the WTA Finals round-robin structure, which forces players into complex tiebreak math regarding sets and games.

“Si je gagne mon match jeudi et que je ne me qualifie pas, ce sera assez étrange,” Gauff said, as reported by Sports Infos. “Je ne sais pas, je ne peux pas en dire plus, attendons l’année prochaine. Tout le monde sait que cela doit changer.”

Reports have linked her comments to potential changes for the 2027 season, which could see the tournament move to Charlotte, North Carolina, compress from eight days to five, expand to 16 players, and return to a direct single-elimination knockout bracket last used in 2002, ski-nordique.net reported.