Second seed Petra Kvitova is the first woman through to the semi-finals of the Sydney International after removing fellow Czech Lucie Safarova in straight sets.
The highest-ranked player left in the draw after Tuesday’s demise of top-seeded titleholder Agnieszka Radwanska, Kvitova advanced to the last four with a 7-6 (7-4) 6-2 defeat of Safarova.
The world No.6 next meets Italian third seed Sara Errani or Bulgarian Tsvetana Pironkova, who play their quarter-final later on Wednesday.
The other two quarter-finals, featuring Americans Bethanie Mattek-Sands and Madison Keys and German fifth seed Angelique Kerber against Spaniard Carla Suarez Navarro, will be played on Wednesday night.