Wild-card entrant Virginie Razzano stunned third-seeded Petra Kvitova 6-7 (6), 7-5, 7-6 (8) on Friday in the Southern California Open quarterfinals.
Razzano, ranked No. 131 in the world, squandered four match points and had to stave off two match points from Kvitova in the third-set tiebreaker before Kvitova double-faulted to end the match at 3 hours, 35 minutes.
"I think I was nervous," Razzano said. "I'm human. I'm not a robot. Sometimes you feel stress. I tried to focus on the points."
The match was the second longest on the WTA Tour this year behind one between Bethanie Mattek-Sands and Anastasia Rodionova that lasted 3:42 at Charleston in April.
The Italian's win over the seventh-ranked Kvitova was her first over a top-10 player since she handed then-No. 5 Serena Williams her first opening-round loss in Grand Slam event at the 2012 French Open.
After winning a tight second set, Razzano was serving at 5-3 in the third set when she wasted three match points on two hitting errors and a double fault.
"In my head, I never lost," Razzano said. "I stayed positive and never thought I could lose."
In the third-set tiebreaker, Kvitova jumped out in front 5-2 before Razzano battled back to even the score. Razzano saved one match point when Kvitova committed an unforced error, then dropped her fourth match point at 7-6. After another unforced error by Kvitova on the Czech's second match point, Razzano hit a forehand winner to set up match point No. 5, which ended with Kvitova's eighth double fault.
Razzano will face the winner of a match between second-seeded Agnieszka Radwanska of Poland and fifth-seeded Sam Stosur of Australia.
In the other quarterfinals, top-seeded Victoria Azarenka of Belarus played Poland's Urszula Radwanska, and fourth-seeded Roberta Vinci of Italy met seventh-seeded Ana Ivanovic of Serbia.