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 Friday in the Open GDF Suez quarterfinals.
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.
Later Friday, second-seeded Petra Kvitova of the Czech Republic faced Frenchwoman Kristina Mladenovic, and No. 3 Marion Bartoli of France played Germany's Mona Barthel.