Jessica Pegula overcame what she described as a "lazy" start to avoid a US Open upset against Leylah Fernandez, while Aryna Sabalenka cruised past Kamilla Rakhimova.

Pegula – who is locked in a four-player battle to end the year's final grand slam as world number one – was facing up to a third-round exit after losing the opening set.

Fernandez, the beaten Flushing Meadows finalist in 2021, rattled off a pair of three-game winning streaks either side of Pegula's lone hold in the opening set.

And Pegula's home fans at Arthur Ashe Stadium would have been nervous when she let a break advantage slip late in the second set, only to respond with another crucial break to level the contest.

The third seed was never going to be denied after storming into a 4-1 lead in the decider, and after her 1-6 6-4 6-3 win, she will face Sorana Cirstea in the round of 16.

But Pegula still feels there is plenty she can improve upon, saying: "I'm really glad I was able to find something there, especially in the second set, to turn it around.

"In the first set, I wasn't really figuring out where I was going to serve and where I was going to hit the first ball. 

"I do think she played a little bit different today than when I've played her in the past. I just wasn't quite moving my feet up to the ball; I was just a little lazy to start off."

5 - Jessica Pegula is the fourth-oldest player in the Open Era to reach 5+ consecutive Women’s Singles Round of 16 at the US Open, younger only than Serena Williams, Martina Navratilova and Chris Evert. Stunning. #USOpen | @usopen @WTA pic.twitter.com/aSbAnXRWRP

— OptaAce (@OptaAce) September 4, 2026

Cirstea advanced with a 6-3 6-3 win over former Roland-Garros champion Jasmine Paolini, while 11th seed Marta Kostyuk overcame Ekaterina Alexandrova 6-3 6-2.

In the other standout match early on Friday, top seed Sabalenka defeated Rakhimova 6-3 6-4 to extend her US Open winning streak to 16 matches.

The two-time defending champion benefited from some ill-timed unforced errors from Rakhimova late in the second, after a hard-fought hold had taken the set to 4-4.

"She played incredible tennis," Sabalenka said of Rakhimova, having teed up a meeting with Taylor Townsend or Diana Shnaider. 

"She pushed me so hard in the second set. She made me work hard and try my best. I'm super happy to close this match in straight sets."

Sweet 16s for Sabalenka and Pegula

Sabalenka remains perfect in 16 US Open matches since losing the 2023 final to Coco Gauff, while she has also reached at least the round of 16 on her last 16 grand slam appearances.

She is the first player on the WTA Tour to enjoy such a streak since Lindsay Davenport, who reached that stage 20 times in a row between Wimbledon in 2000 and the 2006 US Open. The last time Sabalenka failed to reach at least the round of 16 at a grand slam was at the French Open in 2022, when she was defeated by Camila Giorgi.

In addition, Sabalenka now has 16 grand slam victories this season, the fourth straight year in which she has reached that figure. 

She was already one of only five women this century to claim 15+ such wins in at least four straight years, after Venus Williams, Serena Williams, Maria Sharapova and Iga Swiatek.

Pegula, meanwhile, has reached at least the round of 16 at five straight editions of the US Open, with only three players accomplishing that feat at an older age than the 32-year-old – they are Serena Williams, Martina Navratilova and Chris Evert.