Top-seeded Sara Errani of Italy needed more than three hours to beat unseeded Carla Suarez Navarro of Spain 7-5, 4-6, 7-5 in the Open GDF Suez quarterfinals on Friday, while second-seeded Petra Kvitova and No. 3 Marion Bartoli both lost.
Errani will play Dutchwoman Kiki Bertens in the semifinals of the indoor tournament.
Bertens followed up her second-round win against fourth-seeded Dominika Cibulkova of Slovakia with another upset, beating No. 6 Lucie Safarova of the Czech Republic 6-1, 7-5.
There were more surprises in the quarters, as Kristina Mladenovic of France downed second-seeded Petra Kvitova of the Czech Republic 6-3, 6-4, and Germany's Mona Barthel eliminated the third-seeded Bartoli 7-6 (7), 6-4.