Third seed Sorana Cirstea suffered a quarterfinal upset at the $235,000 Aegon Classic, a grass-court Wimbledon tune-up.
Croat Donna Vekic easily upended the Romanian Cirstea 6-2, 6-1 at Edgbaston Priory Club on Friday.
Vekic's semifinal opponent on Saturday will be 16th-seeded Magdalena Rybarikova, who drubbed American Madison Keys 6-3, 6-0. The Slovakian Rybarikova was the Birmingham champion in 2009.
Meanwhile, Slovakian veteran Daniela Hantuchova knocked out 15th-seeded former French Open champ Francesca Schiavone, 6-7 (8-10), 6-4, 7-6 (7-3). Hantuchova, who was the 2011 Birmingham runner-up to German Sabine Lisicki, rallied from a set and 4-1 down to overcome the Italian Schiavone.
Hantuchova awaits the winner between the fifth-seeded former champion Lisicki and upstart American qualifier Alison Riske, who were tied at 6-7 (2-7), 6-2, 2-2 when their match was suspended because of darkness on Day 5.
This week's winner will collect $40,000.