Stan Wawrinka beat 17-time Grand Slam champion Roger Federer, his Swiss Davis Cup teammate, in straight sets to reach the semifinals of the French Open on Tuesday.

Normally composed Roger Federer lost his cool after a series of missed backhands, but still advanced to the third round of the French Open.

Wawrinka was at his exquisite best as he cruised to a 6-4 6-4 6-0 quarter-final victory in one hour, 46 minutes at the US Open.