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Serena Williams' work during a practice session cost her some money.

According to Mike Dickson of the Daily Mail, the tennis player was fined $10,000 for damaging a practice court at Wimbledon after throwing her racket.

As the Associated Press reported (h/t Chris Cwik of Yahoo Sports), the incident took place before the start of the tournament.

Though the All England Club takes its grass courts seriously, Williams nonetheless seems to have prepared herself well for the Grand Slam.

The American has won her first four matches so far at Wimbledon, losing only one set on her way to the quarterfinals. She also won her first mixed doubles match with Andy Murray in straight sets.

Williams is just the No. 11 seed in the competition, but she has won the event seven times already and is playing well enough to be considered a top contender to win another title. The path is even clearer with No. 1 seed Ashleigh Barty out after an upset loss to Alison Riske.

Considering quarterfinalists make at least £294,000 and the winner receives £2.35 million, per WTATennis.com, the 37-year-old likely won't worry too much about the fine.