Sara Errani recovered from a slow start to book her place in the quarter-finals of the Pan Pacific Open with a victory over Marion Bartoli.
The sixth-seed from Italy had dropped the first set against Bartoli before cutting loose to record as 3-6 6-2 6-2 victory.
"It was a tough match on this fast court," Errani said. "I didn't start off well but neither did she. She got a little tired in the second set and that's when I started to play better."
Errani will take on Nadia Petrova in the last eight after the Russian outlasted Petra Martic 7-6 (7-2) 6-7 (7-1) 6-4.
Fifth seed Angelique Kerber found the going easier as she beat Urszula Radwanska 6-1 6-1, while eighth-seeded Samantha Stosur overcame Dominika Cibulkova 6-4 7-5.
