Top seed Maria Sakkari reached her fourth WTA Tour final on Saturday after beating unseeded Romanian Irina-Camelia Begu 6-4, 6-7 (4/7), 6-4 in a three-hour thriller in Saint Petersburg.
Sakkari, ranked seventh in the world, will be seeking her second title when she meets Estonia's Anett Kontaveit after the world number nine saw off Jelena Ostapenko 6-3, 6-4.
Sakkari secured a break at 5-3 in the first set against her 56th-ranked opponent but Begu broke back immediately after the longest rally of the set.
However, Sakkari broke Begu again to take the set.
The incessant breaks of serve continued into the second set as Begu broke Sakkari in the first game but last year's French and US Open semi-finalist broke back for 2-2 and it went to a tie-break.
Begu held her nerve to level the match which prompted Sakkari to hurl her racquet to the ground.
The 31-year-old Romanian maintained her momentum by taking a 2-0 lead in the third set but back came Sakkari.
She served out for the match but not before her valiant opponent had saved two match points.
Kontaveit reached the final with a comfortable victory over former French Open champion Ostapenko.
The 26-year-old Kontaveit, who lost the WTA Finals final to Garbine Muguruza last year, won four tournaments in 2021.