Paula Badosa has taken down the World No. 1.

The 23-year-old Spanish tennis player, currently ranked No. 71 in the world, defeated top-ranked Ashleigh Barty 6-4, 6-3 at the Volvo Car Open on Friday.

Badosa reached the tournament semifinals in her first time at the season’s opening clay-court tournament. And she was rarely pressured by Australia’s Barty on the way to her first victory over a No. 1 player.

Badosa broke Barty’s serve five times, including the last two times Barty served after the second set was tied 3-all.

“I’m still a little bit shocked. I can’t believe what just happened,” Badosa said. “When the ball went out, I was like, ‘What just happened right now?'”

It was the second time in her past four events that Badosa advanced to the semifinals. She’ll face Russia’s Veronika Kudermetova, the 15th seed, on Saturday for a spot in the championship final.

Barty was coming off a victory at the Miami Open last Saturday and looked strong in her first two matches in Charleston. But she fell behind Badosa and struggled to handle her opponent’s serve.

As Badosa got closer to the upset, she worried about Barty’s ability to rally. “Sometimes these matches are very tough to close,” Badosa said. “Today, I’m quite happy that I managed it well.”

Badosa is looking for their first career WTA titles.