US Open, Flushing Meadows
Dates: 30 August - 12 September Start time: 1600 BST
Coverage: Live text commentary on BBC Sport website and mobiles; updates on BBC Radio 5 live; live on Sky Sports
Russia's Vera Zvonareva beat Estonia's Kaia Kanepi 6-3 7-5 to reach the last four of the US Open for the first time.
Kanepi, the 31st seed, served six double-faults in the first set and was broken three times as she struggled to get to grips with the windy conditions.
The errors kept coming from Kanepi in the second set, allowing seventh seed Zvonareva to break her four more times.
Zvonareva will next play either top seed Caroline Wozniacki or Dominika Cibulkova, who meet later on Wednesday.
The match between Zvonareva and Kanepi featured 88 unforced errors, 60 of them from Kanepi, and 11 breaks of serve as the Estonian in particular struggled to deal with the wind which swirls around Arthur Ashe Stadium at Flushing Meadows.
The players exchanged breaks in the first two games of the match before the 26-year-old Zvonareva gained the upper hand with another break in the fifth game.
Kanepi, who knocked fourth seed Jelena Jankovic out in the third round, saved three more break points in her next service game and three more in the ninth before netting a backhand to give Zvonareva the opening set.
Zvonareva was still unable to fully take command of the match however, the second set starting with four consecutive breaks of serve before the Wimbledon finalist was pegged back after taking a 4-2 lead.
But a touch of class from Zvonareva eventually helped her close out the match, a superb lob taking her to within two points of victory and two backhand errors from Kanepi sealing the 25-year-old's fate.
"It was very tough out there for both of us," Zvonareva said. "We tried to show our best and sometimes we had some ridiculous rallies but I was putting all the effort into trying to hang in there no matter what the conditions and I'm really happy the way I pulled it out.
"In these conditions the most important thing is to find the right balance between being aggressive and being patient, between keeping the ball in play and going for your shots. I think I was able to find that balance."
Potenshöjande medel - potenshöjande medel