Madrid: Two-time defending champion Serena Williams withdrew from the Madrid Masters on Friday because of a left thigh injury.
The top-ranked American has had her thigh heavily bandaged during play at the clay-court event, and said the injury occurred during a first-round victory over Belinda Bencic on Sunday.
"It started to get better but, most importantly right now, I just need some time to rest and recover. It's beyond words. It's so frustrating," Williams said in a statement. "This is not the way I wanted this week to end."