Swiss world number four Stan Wawrinka has withdrawn from the ATP Moselle Open in the French city of Metz with an ankle injury, organisers said.
Wawrinka, who was the top seed, suffered the injury during his second-round victory in three sets against Germany`s Dustin Brown on Thursday.
The French Open champion said: "I twisted my ankle at 5-4 in the first set. I need to see the physios. I have put ice on it but it is less good than I thought."
Wawrinka had been due to face fifth seed Philipp Kohlschreiber in the quarter-finals so the German will now advance to the last four on a walkover.