Julia Goerges scuppered the prospect of an all-Russian final at the Kremlin Cup by beating Natalia Vikhlyantseva to a showpiece finale with Daria Kasatkina.
Goerges has already finished runner-up in three tournaments this year and has one more chance to end the six-year drought since her last title.
The German, seeded seventh, needed almost two hours to seal her 6-2 2-6 7-5 victory over her opponent, who struggled with a wrist injury from the opening set.
Kasatkina had a slightly easier outing in the final four, seeing off Irina-Camelia Begu 6-2 6-3.
The 20-year-old has now won five of her six contests against Begu, who required treatment on her right shoulder between sets.
At the Luxembourg Open, Puerto Rico's Monica Puig dispatched the last seed standing.
Puig beat Belgium's Elise Mertens, ranked fifth for the event, with a 6-2 7-5 success.
Puig, the gold medal winner at last year's Olympics in Rio, will take on Germany's Carina Witthoeft for the prize.
Witthoeft, who has 11 tour titles to her name but none since July 2015, bested Pauline Parmentier 7-6 (7/2) 1-6 6-3.
