MIAMI _ Serena Williams withdrew from the Miami Open on Saturday afternoon, citing a left knee injury.
Williams is an eight-time champion of the tournament and has won 23 Grand Slam titles.
"I am disappointed to withdraw from the Miami open due to a left knee injury," Williams said in a release. "It was an amazing experience to play at the Hard Rock Stadium this year and would like to thank the Miami Open for putting on an amazing event. I hope to be back next year to play at this one-of-a-kind tournament in front of the incredible fans here in Miami."
Williams won her opening match 6-3, 1-6, 6-1 against Rebecca Peterson on Friday, and showed no signs of injury during or after the match. The only obstacle she mentioned during her press conference was tricky lighting on Stadium Court. She had said she was "super excited" to play at the event's new venue, Hard Rock Stadium, a place she knows well as a part-owner of the Miami Dolphins.
It is the second tournament in a row from which Williams withdrew. She retired from her third-round match against Garbine Muguruza at Indian Wells, Calif., two weeks ago with a viral illness. She had gone up 3-0 over Muguruza but then lost the next seven games and decided to call it quits.
Williams, who is ranked No. 10 in the world, last won the Miami Open in 2015 and last year lost in the first round to Naomi Osaka, who beat her again at the U.S. Open and took over the world No. 1 ranking.
She has played two tournaments this season, the Australian Open, where she lost to Karolina Pliskova in the quarterfinals and then Indian Wells. Her last title was at the 2017 Australian Open before she took an extended maternity leave later that year.
With the withdrawal, the Miami Open's No. 18 seed Quiang Wang of China will advance to the fourth round in Williams' place.
