Daria Kasatkina advanced to her first grand slam semi-final with a 6-4, 7-6 (7-5) win over Russian Veronika Kudermetova at Roland Garros.

In a quarter-final matchup of 25-year-old Russians, Kasatkina built a 6-1 lead in the tie-breaker 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. She then lost nine of the next 10 points before her brief comeback in the tie-breaker.

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.