Paris: Czech second seed Karolina Pliskova advanced to the fourth round at Roland Garros on Sunday with a 7-5, 6-1 victory over Germany's Carina Witthoeft.
Pliskova, who had won just twice in five previous French Open appearances before this year, will face Paraguay's Veronica Cepede Royg for a quarter-final spot.
Pliskova can replace Angelique Kerber as world number one by reaching the final in Paris.
Elina Svitolina, the fifth seed, also progressed to the last-16 with a 6-4 7-5 win over unseeded Magda Linette from Poland.
Svitolina, who won at Rome a few weeks ago, broke the Pole in the third game and eased her way to the set without facing a break point.
The Ukranian found herself in a bit of a trouble in the second set but used her forehand to dig herself out of the 4-5, 0-30 hole.
In the next game, Linette was broken courtesy of a dead net cord, and then Svitolina served the match out to love to set up a fourth round against qualifier Petra Martic.
Two weeks past his 21st birthday, unseeded Karen Khachanov of Russia became the youngest man to reach the French Open's fourth round since 2009, beating 21st-seeded American John Isner 7-6 (1), 6-3, 6-7 (5), 7-6 (3).
Isner was the last US man in the draw of 11 who entered the tournament.
Khachanov is playing at Roland Garros for the first time. It is only the third major of his career.
The match was suspended a night earlier after the first set because of rain.
Despite hitting eight double-faults, Khachanov won all 23 games he served against Inser, saving four break points. Khachanov converted 1 of 6 break points on Isner's serve, but that was enough.
With inputs from AFP and AP
Updated Date: Jun 04, 2017 17:59 PM