Ash Barty looked like the world No. 1 in the first set, then struggled the rest of the way against No. 52-ranked Marie Bouzkova before completing a 6-0, 4-6, 6-3 win in an Australian Open tuneup tournament on Wednesday.
In the third set, the 2019 French Open champion exchanged three service breaks early before breaking Bouzkova in the eighth game. She ended it with a service winner in the next game.
“Coming off a night match, I’m an early riser to I didn’t get a lot of sleep last night,” Barty said. “I felt in the middle of the match I pressed a little bit … but I was happy to get the win on my terms at the end.”
Barty will play American Shelby Rogers in the quarterfinals of the Yarra Valley Classic and could potentially face Serena Williams in the semifinals.
Williams was playing Tsvetana Pironkova in a night match on Margaret Court Arena.
The Associated Press contributed to this report.