Fourth-seeded Agnieszka Radwanska, who reached the quarterfinal at the Cincinnati Masters, withdrew from the tournament to attend the funeral of her grandfather in Poland.
"Unfortunately, my granddad passed away last Sunday, the funeral is Saturday and I need to be there," Radwanska said, reports Xinhua.
"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 quarterfinals Saturday.
Li now advances directly to the semifinals.
Radwanska outclassed Elena Vesnina 6-0, 6-2 Thursday to reach the quarterfinals.
