Petra Kvitova edges Garbiñe Muguruza in third-set tiebreaker to complete comeback, advance at US Open

Petra Kvitova defeats Garbine Muguruza after thrilling 22-point tiebreaker (0:32)

Petra Kvitova defeats Garbine Muguruza after a thrilling tiebreaker to decide the third set. (0:32)

Petra Kvitova erased a pair of match points and converted her fourth to edge Garbiñe Muguruza 5-7, 6-3, 7-6 (10) on Saturday in a showdown between two-time major champions.

Kvitova just kept coming back -- after dropping the first set, after trailing 5-2 in the third and after being a point from defeat twice at 6-5 -- to advance to the fourth round of the US Open. No. 21 Kvitova on Monday will face No. 8 Jessica Pegula, who defeated qualifier Yuan Yue 6-2, 6-7 (6), 6-0, for a berth in the quarterfinals.

Here's how close this one was: Kvitova won 109 total points, Muguruza 108.

It took the new format final-set tiebreaker to determine the winner. The four Grand Slam tournaments agreed to adopt a uniform system this year, with the third sets of women's matches and fifth sets of men's decided by a first-to-10, win-by-two formula; the US Open used to have the more traditional first-to-seven setup.

"Left everything on the court today," said No. 9 Muguruza, a two-time Slam winner whose departure means the bracket is without six of the top 10 women entering the fourth round.

Kvitova, a left-hander who won Wimbledon in 2011 and 2014, overcame 12 double faults with 14 aces and 50 total winners. She improved to 6-1 against Muguruza, the champion at the French Open in 2016 and Wimbledon in 2017.

Pegula reached the fourth round at the US Open for the first time. She came into Saturday with an 0-2 record in third-round matches at Flushing Meadows, losing at that stage to Kvitova in 2020 and to Belinda Bencic in 2021.

After starting her Grand Slam with a 3-8 record, she has gone 22-7 since, including runs to quarterfinals at the Australian Open each of the past two years and the French Open this year.

Pegula wasted a chance to close out the win Saturday when she held a match point in the tiebreaker but rolled through the third set in a half-hour. Pegula, a 28-year-old American whose parents own the NFL's Buffalo Bills and NHL's Buffalo Sabres, finished with nearly twice as many winners as Yuan, 35-18.

Pegula gets another shot at avenging her 2020 loss to Kvitova on Monday.

"Petra is so hard to play. I feel like when she's on, she blows you off the court. And then sometimes she can be off. ... She's a fighter. When it clicks, it's really difficult," Pegula said, then was sure to add: "I think I'm a much better player now than I was when I played her last time."

Also on Saturday, No. 1 Iga Swiatek advanced by beating Lauren Davis 6-3, 6-4, and No. 6 Aryna Sabalenka defeated Clara Burel 6-0, 6-2. Swiatek won the last five games of the second set and has a potential path to a US Open championship that does not include any past tournament champions.

Swiatek's win was followed by Australian Open runner-up Danielle Collins' 6-4, 7-6 (11-9) win over Alizé Cornet. The 19th-seeded Collins hit a whopping 52 winners against Cornet and moved on to the round of 16 for the first time in her career to play Sabalenka.

No. 26 Victoria Azarenka advanced by defeating Petra Martic 6-3, 6-0. She will face Karolina Pliskova, who edged past Belinda Bencic 5-7, 6-4, 6-3.

The Associated Press contributed to this story.