Third-seeded Slovakian Dominika Cibulkova and fourth-seeded American Jamie Hampton were among Thursday's second-round winners at the Bank of the West Classic.
Cibulkova ousted Swiss Stefanie Voegele, 7-5, 7-6 (7-5), and will next face seven seed Urszula Radwanska in the quarterfinals. The Poland native beat Slovakian Daniela Hantuchova, 7-6 (7-3), 7-6 (7-3).
Hampton defeated fellow American Nicole Gibbs, 7-5, 6-7 (5-7), 6-3. Her next opponent will be Russian Vera Dushevina, who beat American Madison Keys, 7-6 (7-0), 6-2.
The winner of this tournament will receive $125,000.