Greek fourth seed Maria Sakkari (27) beat Marie Bouzkova (24) 7-5 6-4 in a rain delayed semi-final at the Guadalajara Open and will play American Jessica Pegula (28) later on Sunday in the final.
Sakkari had won the opening set of her semi-final on Saturday when the match was halted due to persistent rain.
Returning to the court on Sunday, the Greek had looked to make quick work of her Czech opponent, racing out to a 4-1 lead, before Bouzkova rallied and swept the next three games to level the set at 4-4.
Sakkari struggled to hold serve at 5-4 before breaking Bouzkova to secure her place in her second WTA 1000 event final of the year.
Third seed Pegula had booked her spot in the final on Saturday with a 7-6 (3) 6-1 win over twice Australian Open champion Victoria Azarenka (33).