Serena Williams has pulled out of her fourth-round match at the French Open against Maria Sharapova because of a pectoral muscle injury that won't allow her to serve, she announced Monday.
The two players were coming back from time away -- Williams after having a baby daughter; Sharapova after a doping ban.
It was to be their 22nd head-to-head meeting. Williams has won 19 so far, including the past 18.