China's qualifier Wang Qiang advanced to the semifinals at WTA Prague Open after defeating Poland's Magda Linette 7-5, 6-7(5), 6-4 on Friday.
Wang was overturned by Linette while leading 3-0 in the second set, but then won the third set to eliminate her opponent in an intense three-hour match.
The 30-year-old, ranked No 141, will fight against Russian Anastasia Potapova for a final spot. The last time Wang reached the last four was in Guadalajara in February.
The other semifinal will pit eighth-seeded Marie Bouzkova and Linda Noskova, both from the Czech Republic.