The French Open has only just begun… And, Guillermo Garcia-Lopez has already pulled off the tournament’s biggest upset.

The 30-year-old Spanish tennis player defeated Australian Open champion Stan Wawrinka in the first round at Roland Garros on Monday, 6-4, 5-7, 6-2, 6-0.

Wawrinka, the tournament’s third-seed, was playing his first Grand Slam match as a major champion, but he faded against Garcia-Lopez, currently ranked No. 41 in the world.

Surprisingly, Wawrinka looked listless, nothing little like a guy who was seeded No. 3 behind Rafael Nadal and Novak Djokovic and proclaimed himself “one of the favorites” just a few days earlier

“The match wasn’t good at all,” Wawrinka said. “I don’t have an answer why I didn’t play that good.”

Wawrinka, who had 61 unforced errors and won only 54 percent of the points on his first serve, is the first Australian Open champ to exit in the first round of that year’s French Open since Petr Korda in 1998.

Garcia-Lopez has never been past the third round at a Grand Slam

No. 17 Tommy Robredo of Spain, No. 26 Feliciano Lopez of Spain aand No. 27 Roberto Bautista Agut also advanced.