French Open runner-up Sara Errani was a hard-fought quarterfinal winner at the GDF Suez Open tennis event, but former Wimbledon champion Petra Kvitova was dealt a stunning defeat by Frenchwoman Kristina Mladenovic during Friday's play.
The top-seeded Errani held off game sweet-swinging Spaniard Carla Suarez Navarro 7-5, 4-6, 7-5 in 3 hours, 3 minutes at Stade Coubertin. The match featured 15 service breaks, including eight for the winner.
Kvitova, who captured this Parisian event as well as Wimbledon two years ago, wasn't able to withstand an upset bid from a determined Mladenovic, who came into Friday's bout ranked 87th in the world. The 19-year-old needed just one hour and 19 minutes to deliver a surprisingly easy 6-3, 6-4 decision over the second-seeded Czech star, who committed nine double faults and had her usually powerful left-handed serve broken five times by Mladenovic.
Another upset came when capable German Mona Barthel took out third-seeded Frenchwoman Marion Bartoli in straight sets, 7-6 (9-7), 6-4. The former Wimbledon runner-up Bartoli lost to another German, Angelique Kerber, in last year's GDF Suez finale.
Barthel and Mladenovic will square off in Saturday's semifinals, while Errani's next opponent will be Kiki Bertens after the Dutch lucky-loser bested sixth-seeded two-time Paris runner-up Lucie Safarova, 6-1, 7-5. The Czech Safarova was a finalist at this tournament in 2007 and 2010.
The winner of this $690,000 event will collect $125,000.