Ukrainian Marta Kostyuk, the No 16 seed, advanced to the semi-finals of the Brisbane International presented by ANZ by winning against Russian Mirra Andreeva, the No 6 seed, 7-6 (7), 6-3 on Friday night.
Kostyuk, ranked No 26, will play American Jessica Pegula, the No 4 seed, next.
The Ukrainian beat American Amanda Anisimova, the second seed (6-4, 6-3) and Kazakh lucky loser Yulia Putintseva (6-7 (5), 6-1, 6-0) earlier in the tournament.