Fourth seeded Agnieszka Radwanska, who reaches quarterfinal at the Cincinnati Masters, withdrew from the tournament on Thursday to attend the funeral of her grandfather in her native Poland.

"Unfortunately, my grandad passed away last Sunday, the funeral is Saturday and I need to be there," Radwanska said. "I'm disappointed not to continue with the tournament especially due to my form this week."

She was scheduled to meet Chinese player Li Na at the quarterfinal on Saturday.

Li now advances directly to the semifinals.

Radwanska outclassed Elena Vesnina 6-0, 6-2 earlier Thursday to reach the quarterfinal.