Barty will play American Sofia Kenin in her next match on Thursday, where she could become the first Australian to reach the singles final of the competition since Lleyton Hewitt in 2005.
It took two sets for Barty to down Kvitova 7-6 (8-6), 6-2, with the first set tiebreaker seeing Barty take the lead she needed to push through into the next, winning the second in 35 minutes.
“It’s been absolutely incredible,” Barty said during the post match interview on court.
“I knew that I had to bring my absolute best today against Petra. That first set was so crucial… I just wanted to try to make the most of it and it was really good to get a quick start in the second.”
Wendy Turnbull was the last Australian woman to make it to this stage of the Open.
— US Open Tennis (@usopen) January 28, 2020