Image source, Getty Images
Aryna Sabalenka (right) beat Jessica Pegula 7-5 7-5 to win her first US Open title 12 months ago
BBC Sport tennis news reporter in New York
Elizabeth Botcherby
BBC Sport journalist
US Open 2025
Venue: Flushing Meadows, New York Dates: 24 August-7 September
Coverage: Live radio commentaries across 5 Live Sport and BBC Sounds, plus live text commentaries on the BBC Sport website & app
Defending champion Aryna Sabalenka moved into the US Open semi-finals without playing after Marketa Vondrousova withdrew with injury - setting up a repeat of last year's final against Jessica Pegula.
World number one Sabalenka was set to play unseeded Czech Vondrousova in Tuesday's night session in New York.
But the 2023 Wimbledon champion, whose career has been decimated by injuries, pulled out less than two hours before they were due to take to the court.
Vondrousova was seen with heavy strapping on her left leg as she walked through the Flushing Meadows players' area.
"So sorry for Marketa after all she's been through," Sabalenka wrote on social media.
"She has been playing amazing tennis and I know how badly this must hurt for her."
American fourth seed Pegula earlier swept Barbora Krejcikova aside 6-3 6-3 to advance to the last four.
Czech Krejcikova, a two-time Grand Slam singles champion, represented a dangerous opponent after recovering from a set down and saving eight match points against Taylor Townsend in the previous round.
But an impressive Pegula, who is yet to drop a set here, made serene progress to reach the semi-finals in New York for a second year in a row.
"I feel really comfortable. It's crazy to feel this comfortable on the biggest court in the world with the craziest crowd and the best players," she said.
"Ten years ago I never thought I'd be good at this - but I guess I am."
'Solid' Pegula makes light work of Krejcikova
Image source, Getty Images
Jessica Pegula was runner-up to Aryna Sabalenka at the 2024 US Open
Pegula arrived in New York in poor form, winning just two matches in her previous four tournaments and losing in the first week of a major four times in six appearances.
While she brushed away the cobwebs with routine wins over Mayar Sharif, Anna Blinkova, Victoria Azarenka and Ann Li, the quarter-finals presented a different challenge.
Pegula has previously struggled at this stage - last year's run to the US Open final was her first success in the last eight of a Grand Slam singles draw after six defeats.
But Pegula was unruffled by her 1-6 record, capitalising on a slow start from Krejcikova to race into a 3-0 lead, including breaking to love in the second game.
She dominated the baseline exchanges, hitting deep groundstrokes to trap her opponent at the back of the court and regularly attacked the net to keep her opponent off-balance.
Although Krejcikova pulled it back to 4-3, she was left to rue a poor serving performance, with a double fault at 40-30 opening the door for Pegula to break again in the eighth game and then close out the set.
Krejcikova's serving struggles - winning just 28% of points on her second serve in the opener - continued and a pair of double faults at the start of the second set gifted Pegula an early break.
Pegula was not without her own service wobbles, throwing away a double break lead in the sixth game as Krejcikova sniffed another unlikely comeback.
But she maintained her composure and, a seventh double fault of the afternoon from Krejcikova brought up match point - which Pegula seized at the first attempt.
"I think I've been playing some really good tennis. I've been playing really solid and having good starts," Pegula said.
"She had a couple of really good returns when I was serving at 4-1 and we all saw what she did against Taylor, so I'm happy that we're done."