Top seed Tamara Zidansek, the French Open semi-finalist, will face France's Clara Burel for the Lausanne tennis title following their victories in Saturday's semi-finals.
Slovenia's Zidansek, the world number 50, beat Maryna Zanevska of Belgium 7-5, 6-3 on the clay courts at the Stade-Lausanne tennis club.
Meanwhile 20-year-old Burel, ranked 125, booked her first final on the WTA tour by defeating compatriot Caroline Garcia, the former world number four, 5-7, 6-2, 6-2.
Burel, who received treatment for an ankle injury during the match, looks set to join the world's top 100 whatever the result in Sunday's final.
Burel, a former world number one in the junior rankings, had knocked out the French defending champion and second seed Fiona Ferro in the quarter-finals.
The 32-player Lausanne tournament was not held last year due to the coronavirus pandemic.