Top seed Patty Schnyder made the semi-finals of the W&S Open with a 7-6 (7-1) 6-2 win over Shahar Peer.
Swiss player Schnyder now plays Beth Mattek after the American qualifier upset third seed Jelena Jankovic.
In the other semi-final, fourth seed Daniela Hantuchova will play Akiko Morgami of Japan.
The Slovakian had to battle back to beat Yoon Jeong Cho of Korea 6-7 (1-7) 6-4 6-1 while Morigami beat Indian Sania Mirza 6-4 6-3.
Hantuchova's victory brought to an end a run of 10 tournaments without reaching a semi-final.
Unseeded Morigami, who upset second seed Vera Zvonareva in the previous round, continued her good run of form.
And her quarter-final victory avenged her defeat to Mirza in the first round at Wimbledon.