Martin Klizan will face Dominic Thiem in the St. Petersburg Open final after beating Stan Wawrinka, while Kei Nishikori's long wait for a title goes on following a stunning defeat to Matthias Bachinger in Metz.
Klizan had never beaten Wawrinka in three attempts, but the Slovakian came from a set down to win 4-6 6-3 7-5 on Saturday.
The unseeded Klizan was broken in the opening game of the first semi-final, but claimed the only break of the second set to force a decider.
There was not much in it in the final set as Wawrinka got back on serve at 3-3, only for 2012 champion Klizan to break again for a 6-5 lead and serve out the match.
Left-hander Klizan has won all six finals he has featured in - including one at the Generali Open last month - but Thiem will be the favourite to take the title.
The top seed knocked out Roberto Bautista Agut, winning 6-4 6-3 to move one victory away from a third tournament triumph of the year.
World number eight Thiem had also lost all three encounters with Bautista Agut, yet it was a different story this time around as he served superbly and broke once in each set to reach his first hard-court final for two years.
Nishikori's hopes of claiming a first tour-level title since 2016 were ended by 166-ranked German Bachinger at the Moselle Open.
Bachinger defied the odds to reach his maiden final at the age of 31, winning 2-6 6-4 7-5, and will come up against home favourite Gilles Simon - who saw off Radu Albot 6-3 6-1.
