Serena Williams pulled out of the Yarra Valley Classic on Friday with a right shoulder injury, few hours after her quarter-final victory in the Australian Open tuneup event.
Williams, the winner of 23 Grand Slam singles titles, had set up a mouth-watering semi-final clash against world number one 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"Serena Williams has withdrawn from the Yarra Valley Classic singles draw due to a right shoulder injury," the women's tour said on Twitter.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."
South Africa 69 runs away from winning World Test Championship
Saudi Arabia, Qatar to host fourth round of Asia's World Cup qualifiers
Big target looms but South Africa are confident of chasing it down
De Bruyne joins Italian champions Napoli after Man City exit
Australia topple S Africa top order to take charge of WTC final
