(CNN) -- Defending U.S. Open Champion Kim Clijsters came through a tough three-set quarterfinal on Tuesday to set up a last-four clash with former winner Venus Williams.
The Belgian battled past Australian Sam Stosur 6-4 5-7 6-3, while third seed Williams overcame Italy's Francesca Schiavone 7-6 6-4 to book her place in the semifinal.
Clijsters, 27, and 30-year-old Williams are both chasing their third titles at Flushing Meadows -- Williams having won in 2000 and 2001, and Clijsters in 2005 and after a break from the sport in 2009.
But Clijsters was made to work hard for her semifinal spot by number five seed Stosur, who took a 4-2 lead early on.
Clijsters came back to take the first set, but it was the French Open runner-up Stosur who had the momentum in the second to level the match.
In a windy night on the Arthur Ashe court both players struggled to cope with the conditions and racked up a total of 79 unforced errors and 15 breaks of serve.
However, it was last year's champion who got the better of the weather in the decider to claim her 19th straight victory in New York.
Williams was also challenged by reigning French Open champion Schiavone, with both players also struggling to cope with the windy conditions.
The elder Williams sister raced to a 4-0 lead but was pegged back to 4-4 all by the Italian before going on to take the opener in a close tie break.
Williams also let an early break of serve slip in the second set, but regained her composure to eventually take the match.
Williams will now meet Clijsters in Friday's semifinal for the 13th time in their careers, with their head-to-head tied at 6-6.
"We've had strange matches," Clijsters said of her opponent on the official WTA website."She's capable of doing amazing things. I have to be ready."
"I'm sure we'll have another really good match-up" Williams, who has lost to Clijsters the last four times they have played, added. "I'd like to flip the way it turns out though."