By STEVEN WINE
AP Sports Writer

MIAMI GARDENS, Fla. (AP) - Serena Williams has withdrawn from the Miami Open, blaming a previously undisclosed left knee injury.

Williams showed no signs of injury while winning her opening match against Rebecca Peterson, 6-3, 1-6, 6-1. Williams didn't mention any problems with the knee during a news conference afterward, and the WTA had no information Saturday regarding when she was hurt.

The match Friday was Williams' first in Hard Rock Stadium, the Dolphins' home and the tournament's new center court. The Miami Open moved this year from Key Biscayne, where Williams won eight titles.

She was next scheduled to play No. 18-seeded Qiang Wang, who advances to the fourth round.

Williams hasn't won a tournament since the 2017 Australian Open, before she took a break of more than a year to become a mom.

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