The former Australian Open champion, who had beaten Nadal only once in their previous 13 encounters,??will next face his fellow Swiss countryman Roger Federer for a place in Sunday’s final.
Meanwhile, nine-time French Open champion Nadal, who lost on clay for the fifth time this season,??will head to Roland Garros without a European clay-court title to his name for the first time.
The Spaniard surrendered??four first set points as Wawrinka fought back from the brink to take it and then run away with the match which lasted a little over two hours.
The last time Nadal was beaten so many times on his favorite surface was 12 years ago, and with the French Open nine days away, his status as the favourite is in question.
Nadal dropped out of the top five in the ATP rankings for the first time in 10 years ??falling to No 7 on Monday.