Kristina Mladenovic fought back from a set down to beat Natalia Vikhlyantseva on Saturday and reach the final of the St. Petersburg Ladies Trophy.
In a match with frequent breaks of serve, Mladenovic served particularly poorly in the first set but dominated Vikhlyantseva, the world No. 115, in the second and third to win 4-6, 6-2, 6-2.
Mladenovic, who is ranked 51st, is seeking a first career WTA title in her fourth final appearance.
The 19-year-old Vikhlyantseva's run to the semifinals means she will break into the top 100 for the first time when the rankings are updated on Monday.
Mladenovic will play either second-seeded Dominika Cibulkova of Slovakia or Yulia Putintseva of Kazakhstan in Sunday's final.