Serena Williams pulled out of the Yarra Valley Classic on Friday with a right shoulder injury, few hours after her quarterfinal victory in the Australian Open tune-up event.
Serena, the winner of 23 Grand Slam singles titles, had set up a mouth-watering semifinal clash with world No. 1 Australian Ash Barty after defeating fellow American Danielle Collins 6-2, 4-6 (10-6), on Margaret Court Arena.
"Serena Williams has withdrawn from the Yarra Valley Classic singles draw due to a right shoulder injury," the women's tour said on Twitter.
"Ashleigh Barty advances to the final by walkover."
