But sixth seed Jessica Pegula survived a stiff challenge from fellow American Sofia Kenin to keep her Grand Slam hopes alive, while world No 59 Ashlyn Krueger shocked 21st seed Mirra Andreeva 6-1, 6-4 to reach the third round of a Grand Slam for the first time. She will next meet 16th seed Liudmila Samsonova.

The mixed day for the home nation followed a strong showing a day earlier as defending champion Coco Gauff, 12th seed Taylor Fritz and several other Americans advanced.

Pegula rallied back after dropping serve in the second game of the match to take down 2020 Australian Open champion Kenin 7-6(4), 6-3 on Louis Armstrong Stadium.

The 30-year-old also started the second set down 0-2, but rattled off five straight games to slam the door and remain a perfect 11-0 against American opponents this year.

Pegula, who has never progressed beyond the quarterfinals at a major, will next meet Spain’s Jessica Bouzas Maneiro.

“I started serving a little better. I thought I served pretty well in the moments that I had to,” Pegula said.

“I knew I had chances to break but, I mean, she’s really tough. She’s a good returner and when she’s hitting her shots and getting really good depth that makes it really hard.”

Korda’s hopes of reaching the third-round at the US Open for the first time fell short as the 16th seed struggled to hold serve against the Czech Republic’s mixed doubles Olympic gold medalist Tomas Machac. He was beaten 6-4, 6-2, 6-4.

Korda struck first with a break in the sixth game of the first set, but quickly ceded that momentum and dropped serve in the next game, netting a backhand and launching a forehand long for two of his 37 unforced errors on the day.

After dispatching 11th seed Danielle Collins in the first round, unseeded Caroline Dolehide’s US Open singles aspirations were ended by Italy’s Sara Errani in a tight 7-5, 7-5 tussle.

Tommy Paul, the 14th seed, will look to stamp his ticket into the third round on Thursday evening when he takes on Australia’s Max Purcell.