Defending champion Stefanos Tsitsipas reached the Open 13 final with a 7-5, 6-3 win against Alexander Bublik on Saturday.
The second-seeded Greek had six aces and broke his strong-serving Kazakh opponent's serve three times, dropping his own once. Playing only his third semifinal at this level, Bublik competed well and hit eight aces.
"I know he can be quite unexpected. You don't know what to expect," Tsitsipas said. "I am really happy with myself that I found a balance and I didn't panic when things got tight. That is a great attitude that I put out on the court."
The 21-year-old Tsitsipas will aim for his fifth career title on Sunday against seventh-seeded Felix Auger-Aliassime.
The 19-year-old Canadian beat 35-year-old Frenchman Gilles Simon 7-5, 7-6 (2) for a second straight final, after losing in the World Tennis Tournament final against Gael Monfils in Rotterdam last weekend.
Having reached his fifth career final, Auger-Aliassime is aiming to win his first title.
He leads Tsitsipas 2-1 in career meetings, with all of those matches played last year but none of them on indoor hardcourts.