Top seed Simona Halep is out of the Aegon Classic in Birmingham after losing 2-6 6-0 7-6 (7-4) to Kristina Mladenovic in the quarter-finals.
The Romanian, bidding for a fourth singles title of the year, was overpowered by the world number 43.
Halep, 23, reached the semi-finals of Wimbledon last year, while France's Mladenovic has never been past the first round in three appearances.
Fourth seed Angelique Kerber is now the top-seeded player left in the draw.
The German beat Katerina Siniakova of the Czech Republic 6-2 6-4.
Mladenovic will face sixth seed Karolina Pliskova in the semi-finals after she followed up her win over Britain's Johanna Konta with an impressive 6-2 6-2 victory over third seed Carla Suarez Navarro.
Kerber will take on compatriot Sabine Lisicki, who beat Slovakia's Daniela Hantuchova 7-6 (7-2) 6-2.