Stephens was hailed as the natural successor to the Williams sisters when she made her first grand slam semi-final in Australia in 2013, but had struggled to back it up until now. As always, Williams remained unperturbed by her own errors or the strong play of her opponent, and eventually overcame a 1-3 deficit in the first set by winning the next five games to take the set 6-3.
Two-time Wimbledon champion Petra Kvitova has set up a mouth-watering quarter-final clash against seven-time Grand Slam champion Venus Williams after defeating pre-tournament favorite Garbine Muguruza in straight sets on Sunday at the ongoing US Open.
Kvitova has won four of her previous five matches against Williams.
Kvitova will next face local favourite Venus Williams, who has a 1-4 record against the Czech.
"Everything she's (Kvitova) gone through..."
Despite her loss, 27-year-old Kvitova can take great heart from her displays in NY, which comes just nine months after being the victim of a knife attack in her home.
"I am focused on myself and being as aggressive as possible".
Next up for Williams is another comeback kid in 16th seed Stephens, who only began her season at Wimbledon after foot surgery sidelined her for almost a year.
Williams is the oldest woman entered at 37 but was this year's Wimbledon and Australian Open runner-up.
"Every moment I'm living right now is something special", Kvitova said. Coco Vandeweghe and Madison Keys will attempt to complete a full house of American women in the last four when they take on world No 1 Karolina Pliskova and Kaia Kanepi respectively.
Despite the absence of Serena Williams, the year's concluding Grand Slam tournament could yet produce an all-American semi-final line-up.
Oh, and it's all going down at a stadium named for an African-American tennis player, Arthur Ashe. The Argentine notched the biggest win of his career against Federer in the 2009 U.S. Open final, and every time he comes to NY it seems like he is resonating with that memory.
"It would be fantastic to play him in the final", Carreno Busta said of facing countryman Nadal in the final.
Sloane Stephens of the United States clinched a quarterfinal victory over 16th seeded Latvia's Anastasija Sevastova by 6-3, 3-6, 7-6 and reached her first ever US Open semifinal on Wednesday. She came to the US Open on a protected ranking, and eventually came through three tough three-setters over three seeds to make her first US Open semi-final.
It's quarterfinal time at the U.S. Open and we're previewing all eight matchups on the men's and women's side. Pliskova reached the final in NY last season, taking out both Williams sisters in the process.
- Top seeds Henri Kontinen and John Peers enjoyed a 6-3 6-4 victory over American Nicholas Monroe and Australian John Patrick-Smith in the men's doubles quarter-finals.
The victor will face either 83rd-ranked American Sloane Stephens, who missed 11 months with a left foot injury before returning at Wimbledon, or Latvian 16th seed Anastasija Sevastova.
Kvitova served two double faults in her opening service game but it was Williams who buckled first, double faulting on break point to gift the Czech an early 2-1 advantage.