Top seed Roger Federer continued his quest for a 10th Swiss Indoors title with a 6-4 6-4 semi-final victory against Stefanos Tsitsipas of Greece.
Federer, 38, has won his home title in four of the last five years.
In his 16th Basel semi-final, the world number three saw off seventh-ranked Tsitsipas, 21, in one hour, 20 minutes.
In Sunday's final he will play 20-year-old Australian Alex de Minaur, who beat USA's Reilly Opelka 7-6 (7-2) 6-7 (4-7) 7-6 (7-3) in two hours, 33 minutes.
World number 28 De Minaur maintained his 100% record against the 6ft 11 American 22-year-old with his fourth victory against him this year.