World No 3 Jessica Pegula shook off a lackluster opening set to overcome Leylah Fernandez of Canada in three sets on Friday, advancing to the US Open fourth round.
In a battle of former US Open finalists, Pegula defeated Fernandez 1-6, 6-4 6-3, concluding the match with a swinging backhand volley winner.
Pegula said after the match she knew she was "going to have to dig deep" to turn things around after moving sluggishly in the first set.
"I never feel comfortable playing her," Pegula said of Fernandez, a tricky player whose mix of hard and off-pace shots demands maximum focus.
Pegula will face Sorana Cirstea for a place in the quarterfinals after the Romanian veteran beat Jasmine Paolini 6-3, 6-3, with a potential clash with top-seed and two-time defending champion Aryna Sabalenka possibly looming in the semifinals.
Sabalenka, who advanced earlier Friday, beat Pegula in the final of the 2024 US Open and again last year in the semis.
Fernandez easily won the first set, capitalising on a rash of errors from the American, who struggled to read the varied spin and speeds of her left-handed opponent's serve.
But Pegula, who has won two titles in 2026 and reached the final of the big Cincinnati warmup tournament, played with greater patience in the second set, waiting for the right moment to step up the power and seize control of points.
The two players exchanged breaks at the end of the set, with Pegula finally edging through when Fernadez couldn't handle the trajectory of a ball that nicked the net on the way over.
The third set began in the same see-saw manner, but a turning point came when Fernandez was unable to capitalise on two break points at 1-1.
Pegula won that game, broke in the next and held the rest of the way.