Wawrinka, the Swiss star who beat Novak Djokovic in last year's men's singles final, lost the first and third sets against an opponent best-known for beating Rafael Nadal at Wimbledon in 2010.

The third seed had beaten 59th ranked Rosol in the semi-finals of the Geneva Open last week but made 46 unforced errors in a topsy-turvy display today.

He eventually won 4-6, 6-1, 3-6, 6-3, 6-4 in three hours and 11 minutes.

“It was a really tough match, the conditions were slow and heavy,” he said.

“I didn’t play my best tennis and made a lot of mistakes - but he was playing really well.

“It’s a good thing to get through, but it’s never the best to start with a five-set match and not play your best.

“I’m really happy with the way I found solutions.

"Now I have the chance to keep improving for the rest of the tournament.”

On another rain-affected today, Japan's fifth seed Kei Nishikori secured a 6-1, 7-5, 6-3 win over Simone Bolelli of Italy.

Canada's eighth seed Milos Raonic overcame former top-10 player Janko Tipsarevic of Serbia 6-3, 6-2, 7-6.

Second-seed Agnieszka Radwanska was among the winners in the women's draw, dispatching Serbia's Bojana Jovanovski 6-0, 6-2.

The Pole is seeking to improve on her best French Open finish of the quarter-finals in 2013.

Sixth-seed and 2014 runner-up Simona Halep thrashed Japan's Nao Hibino 6-2, 6-0, while Tsvetana Pironkova of Bulgaria knocked out Italy's 16th seed Sara Errani 6-3 6-2.