WTA Finals: Rybakina out with illness, Kostyuk loses to Noskova, Gauff beats Pegula

Rybakina said in a statement that she was "really sad" to withdraw and that her "body is just not physically ready to compete". She plans to rest and prepare for 2027, and said she "can't wait to be back in Indian Wells in March". She finished the season with a 54-14 record and four titles, at the Australian Open, Stuttgart, the US Open and Ningbo, and had already secured the year-end No. 1 singles ranking in Tokyo. The WTA's race table before the event had her on 8,099 points, ahead of Aryna Sabalenka on 6,485 and Mirra Andreeva on 6,306.

Kostyuk, the first alternate, took her place in Group 1 and found out on Saturday that she would play. She has had a right wrist injury since the Billie Jean King Cup final in September, and told the WTA that she had been in pain every day for three months and that Sunday was only the second day without it. She had lost her last four matches and said she is healthy but short of practice.

Noskova and Gauff win in Group 1

Noskova, the eighth seed, is 21 and ranked No. 8. She said she had one day to get used to a different opponent but that her preparation was the same, and that she wanted to avoid long rallies. She won the first set in just over half an hour, broke for 4-2 in the second and did not drop another service game. It was the fourth meeting between the two this season: Kostyuk won in Madrid, and Noskova won at Wimbledon and the US Open, and now here.

The WTA lists some records for the winner. Noskova is the third-youngest Czech to win a WTA Finals match, behind Helena Sukova and Petra Kvitova. She has 41 wins this year including Billie Jean King Cup play, a career high, with her fifth win over a top-10 player this season, and she has won her past 37 matches after taking the first set.

Gauff, the fourth seed, beat fifth seed Pegula after trailing in the second set. She rallied from 5-1 down, held a match point at 6-5, and lost the tiebreak after Pegula saved it. In the decider she broke in the first game, went 3-0 up and won the set 6-2. It was her sixth win in 11 meetings with Pegula and her third straight over her, all of them this year.

Day 2: Sabalenka v Muchova opens Group 2

Group 2 starts on Monday. Second seed Aryna Sabalenka plays seventh seed Karolina Muchova at 12 pm local time, followed by third seed Mirra Andreeva against sixth seed Elina Svitolina. Muchova leads Sabalenka 3-2 in their meetings, though Sabalenka won their only match this year, in Brisbane in January. Andreeva and Svitolina are level at 1-1, and Svitolina won their meeting at the Australian Open.

The WTA notes several first-timers and returnees. Sabalenka is making her sixth straight Finals appearance. Muchova is a first-timer and was the last to qualify, after a Doha title and a second Grand Slam final at Wimbledon. Andreeva is also a first-timer, a Roland Garros champion this year who won Indian Wells in 2025. Svitolina is back for a fourth time and for the first time in seven years, having won the title in 2018.

The doubles draw has eight teams as well. On Sunday the first seeds, Katerina Siniakova and Taylor Townsend, played Sara Errani and Jasmine Paolini, and fourth seeds Cristina Bucsa and Nicole Melichar-Martinez played sixth seeds Ellen Perez and Demi Schuurs. Monday's doubles are Gabriela Dabrowski and Luisa Stefani against Elise Mertens and Zhang Shuai, and Guo Hanyu and Kristina Mladenovic against Hsieh Su-wei and Jelena Ostapenko.

Gauff and Pegula were separated by only three points in the race to the Finals, 5,763 to 5,760, and the WTA's table put Andreeva third on 6,306. Rybakina, for her part, went through the 2025 Finals in Riyadh unbeaten as the last player to qualify, so the title she was defending was won without losing a match.

Under the round-robin format each player faces the other three in her group, and the top two from each group meet in the semi-finals. Group 1 still has two matches for each player, with Gauff and Noskova starting with wins.