Andrea Petkovic held off a fighting display from Barbora Zahlavova Strycova to claim a place in the final of the BNP Paribas Fortis Diamond Games in Antwerp.
The German third seed looked to be heading for an easy win when she raced into a 4-0 lead in the opening set, but her Czech opponent clawed back the deficit before eventually taking things to a tie-break.
Petkovic came out on top in that and then broke in the opening game of the second set to once again put herself in the driving seat.
However, Zahlavova Strycova refused to give in and another tie-break was needed to settle matters, with Petkovic emerging a 7-6 (7/2) 7-6 (8/6) winner after two hours and 24 minutes on court.
World number 12 Petkovic will now take on fifth seed Carla Suarez-Navarro for the title on Sunday.
The 26-year-old Spaniard expended far less energy in a 6-2 6-2 victory over eighth seed Karolina Pliskova of the Czech Republic.
