Andrea Petkovic withstood a stern test from Barbora Zahlavova-Strycova to book her spot in the WTA Diamond Games final on Saturday.
Petkovic, who is guaranteed to re-enter the top 10 regardless of the outcome on Sunday's final against Carla Suarez Navarro in Antwerp, needed almost two and a half hours to pick up a 7-6 (7-2) 7-6 (8-6) victory.
Zahlavova-Strycova will rue a first-set collapse after she raced into a 4-0 lead, only for Petkovic to fight back and claim an opener that saw eight breaks of serve.
The German broke immediately at the start of the second, but handed the advantage back in the eighth game as the match headed for another tie-break.
Zahlavova-Strycova saw another chance go begging as she served for the set at 6-5, but again Petkovic showed her fighting spirit to rebound and move in to the final.
Petkovic will now play for a sixth career title and it marks another step on a superb climb back up the rankings after a series of injuries left her 192nd in the world in October 2012.
Earlier, fifth seed Navarro earned a measure of revenge on Karolina Pliskova in a 6-2 6-2 triumph.
The Spaniard was beaten in three sets when the pair faced off in Sydney last month, Pliskova hitting 15 aces on that occasion.
However, the Czech was out of sorts on this occasion, landing just 37 per cent of her first serves, and Navarro punished that wayward serving with five breaks as she wrapped up victory in little over an hour.
Navarro can now look forward to the first Premier-level final of her career.