Elena Rybakina ensured she will leave the US Open as the new world number one following her victory over China's Zheng Qinwen on Wednesday, while 2023 champion Coco Gauff recovered from a slow start to set up a semi-final clash with the Kazakh.
A day after Ben Shelton took out defending champion Carlos Alcaraz in the latest-finishing match at Flushing Meadows, Alexander Zverev wrapped up the action in double-quick time by thumping Botic van de Zandschulp 6-2 7-5 6-1.
The German top seed will take on Karen Khachanov in the next round after the Russian went through when Alexander Blockx retired while trailing 6-2 7-5 3-2.
With Aryna Sabalenka (top seed), Rybakina (second), Jessica Pegula (third) and Gauff (fourth) all through to the final four, it marks the first time all four top-seeded women have reached a Grand Slam semi-final since Wimbledon in 2009.
Zheng had earned a reputation as a comeback artist at Flushing Meadows but ran out of gas on Wednesday, losing 3-6 6-1 6-4 as Rybakina chipped away at her defenses after overcoming early mistakes at Arthur Ashe Stadium.
"It's tough to find words," said Rybakina, who will dethrone Sabalenka at the top of the world rankings on Monday. "It wasn't maybe the highest level but I'm glad I pushed through."
US fan favorite Gauff then got off to a dreadful start before recovering to beat Russian fifth seed Mirra Andreeva 2-6 7-6(7) 6-2.
Gauff improved her level dramatically as the match wore on, drawing inspiration from compatriot Frances Tiafoe's recovery from two sets down the previous evening as she saved two match points in the tiebreak.
"Elena - she's the new world number one so it's going to be a tough match," Reuters quoted Gauff as saying. "I'm looking forward to the battle. These are the moments you live for."
Zverev started his campaign with back-to-back five-set matches and made another sluggish start against his Dutch opponent.
"I think you saw in the first two rounds, I really didn't play well," Zverev said.
"In other tournaments I'd be out in the first round, but here I can fight back and play best of five sets, play 4-1/2 hours ... I'm definitely happy to be in the semi-finals."
The French Open champion was on the brink of losing the second set but held firm and faced little resistance thereafter to ease into his third New York semi-final.
With 23 Grand Slam match wins this year, Zverev surpassed Boris Becker's German men's record of 22 from 1989.
His next opponent Khachanov has made the final four at Flushing Meadows for the first time since 2022 and can look forward to a rematch of their Tokyo Olympics final when Zverev won the gold medal.
