Second-seeded Dominika Cibulkova beat Urszula Radwanska 7-6 (3), 6-3 on Thursday to advance to the Bank of the West Classic quarterfinals.
Cibulkova, the 2013 champion, was ahead 5-2 in the first set before Radwanska rallied to tie it. Cibulkova, playing in her first match of the week after a first-round bye, cruised in the first-set tiebreaker and had no problems in the second set. She will face No. 5 seed Misaki Doi of Japan on Friday.
CiCi Bellis beat fellow American Sachia Vickery 4-6, 6-4, 6-3 and will face top-seeded Venus Williams on Friday night. Bellis, a 17-year-old wild card, broke Vickery in the seventh game of the third set, held serve in the eighth and broke again for the win.
Alison Riske dropped the first five games of her match, but rallied to beat qualifier Ana Bogdan 3-6, 6-2, 6-4.