(CNN) Seven-time Wimbledon champion Serena Williams has been handed a $10,000 fine for damaging one of the practice courts with her racquet.

The incident occurred on an outside court during a training session on June 30, the day before this year's grass grand slam began, according to organizers.

"I haven't really thought about it, to be honest," Williams, who has won more than $88 million in her career, told reporters after winning her quarterfinal against compatriot Alison Riske Tuesday.

"I just threw my racquet. I got fined."