PARIS, France - Daria Kasatkina is through to her first ever Grand Slam quarterfinal after defeating World No.2 Caroline Wozniacki in straight sets at Roland Garros.

With her 7-6(5), 6-3 victory over the reigning Australian Open champion extends her 2018 record over Wozniacki to 3-0, and puts a damper on the Dane's bid to return to the WTA World No.1 title.

One of six women who entered Roland Garros with the chance to end the fortnight at World No.1, Wozniacki had to win the title to secure the top ranking. If she reached the quarterfinals, current No.1 Simona Halep - last year’s finalist here - would have had to return to the final to have a chance at hanging onto the ranking. With Wozniacki falling to Kasatkina in the fourth round, she’s just eased Halep’s chances considerably.

Read more: Battle for No.1: Can Wozniacki or Muguruza unseat Halep in Paris?

“It was [an unexpected] change the court from Suzanne Lenglen to Philippe Chatrier,” Kasatkina admitted to press later. “This was a little bit weird point for me, like when I serve when I just came on the court. But I think this is important experience, and I'm really happy at the end I was mentally more tough, I think.”

Kasatkina was ahead a set and 3-3 on Sunday when play was suspended due to darkness. Upon resumption, the Russian stayed aggressive and went on a three-game tear to close out the match in exactly two hours total.

“I think the slower the surface is, the better for her,” Wozniacki said afterwards. “She has very good hands and good angles and everything, so I think that suits her.

“I honestly didn't think I played badly this morning. She didn't miss one ball, and she was playing very close to the lines. I was trying what I could, but it just wasn't enough today.

“She just won the three games and that's it. That's tennis sometimes.”

Up next, Kasatkina will take on another reigning Grand Slam champion when she faces the No.10 seed Sloane Stephens in the quarterfinals. The American had little trouble advancing against No.25 seed Anett Kontaveit yesterday, dropping just two games to win 6-2, 6-0.

“I didn't see [any] of her matches here,” Kasatkina said. “Of course I expect from her 100% of her abilities because quarterfinals of the Grand Slam, of course. And for sure, if I want to go further I have to also show my best.

"I think it's going to be pretty interesting match to watch, because we are both, like, playing more or less and have to prepare.”