Viktorija Golubic ended teenager Rebeka Masarova's unexpected run at the inaugural WTA Ladies Championship Gstaad, but there will be no all-Swiss final after Kiki Bertens beat top seed Timea Bacsinszky.
World number 797 Masarova stunned fifth seed Annika Beck by securing a 7-5 6-2 victory to reach the last four of a rain-affected tournament in the Swiss Alps on Saturday.
But the 16-year-old, given a wildcard for the clay-court tournament in her homeland after winning the French Open junior title, was unable to get the better of compatriot Golubic later in the day.
The unseeded Golubic ousted Carina Witthoeft by winning two tie-breaks before wrapping up a more straightforward 6-3 6-2 triumph over Masarova to stand just one win away from her first WTA title.
Like Masarova, Bertens also had to play two matches on the penultimate day of the tournament, but the third seed was able to come through both to reach Sunday's final.
Bertens, eyeing a second title of the year, outclassed Irina Khromacheva with a 6-3 6-1 quarter-final win and followed that by dumping out Swiss number two Bacsinszky 7-5 7-6 (7-1) in the Roy Emerson Arena.
Third seed Bertens withdrew from the doubles with a calf injury following her semi-final success, giving herself extra time for treatment ahead of another showdown.