Australian Open champion Stanislas Wawrinka of Switzerland crashed to a shocking second-round defeat at the Madrid Open on Tuesday when he was upset 1-6 6-2 6-4 by Austrian qualifier Dominic Thiem.

Third-seeded Wawrinka, who followed up his title in Melbourne with a win at last month's Monte Carlo Masters, started strongly against the 70th-ranked Thiem, who at 20 years and eight months is the youngest player in the top 100.

Wawrinka lost his way in the second set and was unable to recover in the third as Thiem pulled off his first win over a top 10 player to secure passage to the third round and a meeting with 15th seed Mikhail Youzhny of Russia or unseeded Feliciano Lopez of Spain.

Wawrinka told a media conference he had had trouble adjusting to the conditions in the Spanish capital, where the higher altitude and thinner air helps the balls fly faster than a clay court at sea level.

"It's never easy to (adjust), especially here ... it's flying a little bit," said the 29-year-old, who lost to Rafael Nadal in last year's Madrid final.

"He was finding his game and I was hesitating and not playing my best," Wawrinka said of Thiem. "He's a good player. We all know that. We all see that, especially since the beginning of the year.

"I'm not surprised, because I know him. He was going for it and he deserved to win."

For his part, Thiem was a bit incredulous.

"I cannot really believe it," he said. "Of course I was a little bit nervous, but it wasn't the reason for the first set; his pace was just too high for me.

"I played a good game at the beginning of the second set to break him and then I started to get used to the pace and angles and his game.

"This year I have played very good so far. Also very consistent. I think that's it's more important, to play almost every day against these top guys to increase your own level."

Thiem was joined in the last 16 by fifth seed David Ferrer, who had to dig deep to knock off Spanish compatriot Albert Ramos 7-6 (6) 5-7 6-3.

Top seed and defending champion Nadal, the world No 1, begins his title defence with a second-round match against unseeded Argentine Juan Monaco on Wednesday before seventh seed Andy Murray of Britain takes on Spain's Nicolas Almagro.

Nadal's chances of success have been boosted by the withdrawal of both second-ranked Serb Novak Djokovic, who has an arm injury, and Roger Federer.

(China Daily 05/08/2014 page24)