Petra Kvitova withdrew from the St. Petersburg Ladies Trophy in Russia due to illness on Thursday.
The No. 3 seed was set to face Russia’s Ekaterina Alexandrova in the quarterfinals but pulled out of the competition.
“I’m really sorry to withdraw from the St. Petersburg Ladies’ Trophy due to illness,” Kvitova said in a statement.
“I wasn’t feeling well during my match yesterday and hoped I would feel better today, but unfortunately, that’s not the case.
“I’m sorry not to play in front of the fans here in this beautiful city. I wish the tournament a great finish and hope to be back again next year.”
The withdrawal means that Alexandrova advances into the semifinals for the second time this season.