Australian Samantha Stosur will face top seed Caroline Wozniacki in the semi-finals of the Japan Women's Open after winning her way past American Jill Craybas.
Stosur was in fine form from the outset against Craybas, winning comfortably 6-1 6-3.
Top seed Wozniacki was made to work hard by Canada's Aleksandra Wozniak before securing her place against Stosur with a 6-2 6-7 (1-7) 6-2 win.
The Dane appeared to be on her way to another comfortable win when she took the first set, but her near-namesake fought back taking a tense second by storming through the tie-breaker.
But Wozniacki upped her game in the final set, finding rhythm on serve and breaking twice to finish the match off with relative ease.
The other semi-final will see India's Samia Mirza face Italian fourth seed Francesca Schiavone after both players advanced courtesy of injuries to their quarter-final opponents.
Unseeded Mirza was 6-4 2-0 up against second seed Marion Bartoli when the Frenchwoman had to withdraw with a shoulder injury, while Schiavone was handed a walkover with Melinda Czink unable to take the court because of a foot problem.
Top seed Flavia Pennetta clinically took her chances to defeat Ioana Raluca Olaru 7-5 6-2 and book a semi-final place at the Generali Ladies tournament in Linz.
A closely-fought encounter was decided on Pennetta's ability to convert her break-point opportunities when they came along.
Pennetta converted five of her seven chances to tie up victory in one hour and 33 minutes. In contrast her 20-year-old Romanian opponent wasted five of seven break chances.
Pennetta will meet third seed Yanina Wickmayer in the last four after the Belgian defeated Sara Errani 7-5 6-3.
Poland's Agnieszka Radwanska, the second seed, won through to her third consecutive WTA Tour semi-final with a 6-3 7-6 (11/9) victory over Czech Republic's Lucie Safarova.
Radwanska will meet another Czech in the last four after Petra Kvitova upset fourth seed Carla Suarez Navarro 7-5 6-4.
Generali Ladies tournament
1-Flavia Pennetta (Italy) bt Ioana Raluca Olaru (Romania) 7-5 6-2
2-Agnieszka Radwanska (Poland) bt 7-Lucie Safarova (Czech Republic) 6-3 7-6 (11-9)
3-Yanina Wickmayer (Belgium) bt 8-Sara Errani (Italy) 7-5 6-3
Petra Kvitova (Czech Republic) bt 4-Carla Suarez Navarro (Spain) 7-5 6-4
Japan Women's Open
1-Caroline Wozniacki (Denmark) bt 6-Aleksandra Wozniak (Canada) 6-2 6-7 (1-7) 6-2
Sania Mirza (India) bt 2-Marion Bartoli 6-4 2-0 ret.
3-Samantha Stosur (Australia) bt Jill Craybas (USA) 6-1 6-3
4-Francesca Schiavone (Italy) bt 7-Melinda Czink (Hungary) walkover.