Daria Kasatkina advanced to her first Grand Slam semifinal with a 6-4, 7-6 (5) win over Veronika Kudermetova at Roland Garros.

The 20th-seeded Kasatkina will next face either top-ranked Iga Swiatek or 11th-seeded Jessica Pegula.

In a quarterfinal matchup of 25-year-old Russians, Kasatkina built a 6-1 lead in the tiebreaker and finally clinched it on her fifth match point, beating Kudermetova with a backhand drop shot.

The 29th-seeded Kudermetova took a medical timeout to have her left foot taped after she held for a 6-5 lead in the second set. But she then lost nine of the next 10 points before her brief comeback in the tiebreaker.

Kasatkina has not dropped a set in her Roland Garros run. She hit only 16 winners but Kudermetova made 50 unforced errors — twice as many as Kasatkina.