Australian Open champion Stanislas Wawrinka crashed out of the French Open in a huge first-round shock at Roland Garros.

The third seed never looked comfortable in heavy conditions after a wet day in Paris and fell 6-4 5-7 6-2 6-0 to Spain's Guillermo Garcia-Lopez.

It was a nasty first-round draw against a very capable clay-courter but few would have predicted an upset nor the abject form Wawrinka showed for much of the match.

When the 29-year-old won the Masters title in Monte Carlo last month it looked like he could potentially add the French Open crown to the one he so stunningly won in Melbourne in January.

But he was in trouble virtually from the start on Court Philippe Chatrier and became the first Australian Open champion to lose in the first round in Paris since Petr Korda in 1998.

Wawrinka, who has struggled at times with his new status as a major favourite, made the quarter-finals in Paris last year for the first time having reached the fourth round in the previous three years.