Paris, June 5: Czech second seed Karolina Pliskova and Ukrainian fifth seed Elina Svitolina advanced to the women's singles fourth round of the French Open tennis championships here, after defeating Germany's Carina Witthoeft and Poland's Magda Linette, respectively, on Sunday.

"I don't think that I'm playing the best tennis. It's good, and I can still improve," Pliskova was quoted as saying by Xinhua news agency.

"The second set was the best so far that I played in this tournament. But still there are some things that I want to improve and play better," she added.

For the third year in a row, Svitolina marched toward the fourth round of the tennis tournament, defeating Linette 6-4, 7-5 in an hour and 28 minutes.

The 22-year-old winner of the Taipei, Dubai, Istanbul and Rome tournaments will play the next round against Croatian Petra Martic, who defeated Latvian Anastasija Sevastova, 6-1, 6-1.

The 11th-seeded Caroline Wozniacki overcame the eighth seed Svetlana Kuznetsova 6-1, 4-6, 6-2 in a highly-anticipated round of 16 clash.

"I knew it was going to be a tough match going in. My game plan was working and kind of kept her on her toes with putting in some dropshots and mixing up the pace," said Wozniacki.

Kuznetsova said: "Caroline was defending very good today and playing very deep, close to the lines. I felt like I lost my chances."

Meanwhile, French Open debutant Karen Khachanov of Russia knocked out the United States' John Isner to set-up the fourth round against world No.1 Andy Murray.

The 21-year-old Russian, World No.53, needed three hours to beat the World No.22 7-6 (1), 6-3, 6-7(5), 7-6(3).

IANS