Britain's Johanna Konta was knocked out of the Aegon Classic in the second round by American Coco Vandeweghe.
Konta, who was the highest seed left in the Birmingham tournament, won only 11 points in losing the first set in 24 minutes to the world number 30.
Konta, the world number seven, grew increasingly frustrated as she was beaten 6-1 6-3 loss in 64 minutes.
Vandeweghe will play Spain's Garbine Muguruza in the last eight after the Spaniard overcame Alison Riske 6-1 6-4.
World number five and second seed Elina Svitolina may miss Wimbledon because of a foot problem sustained in her defeat by Italian qualifier Camila Giorgi.