London, Jul 11 (IANS): Luxembourg's Gilles Muller knocked off Spain's Rafael Nadal 6-3, 6-4, 3-6, 4-6, 15-13 in an epic match in the round of 16 at Wimbledon here.

The 34-year-old Muller needed four hours and 48 minutes to pull off his second upset over the Spanish star at the All England Club on Monday, Efe news reported.

Muller stunned Nadal at Wimbledon in 2005, when the Spanish star was just 19.

The 31-year-old Nadal, who has won 15 Grand Slam singles titles, entered the match on a quest for his third title at Wimbledon after winning his 10th French Open title on June 11.

The Spanish star took the trophy home in 2008 and 2010, with his first title at the All England Club coming over Swiss great Roger Federer in a five-set thriller ranked by many observers as the greatest tennis match of all time.

Muller, the number 16 seed, entered Wimbledon with 10 wins on grass, the most of any man on the ATP Tour, and fresh off winning the title on grass at Hertogenbosch.

"I haven't actually realized what has just happened," the winner said afterward. "I am tired. I am glad it's over. I was already thinking about the match having to end and coming back tomorrow."

"It's just a great feeling to be winning that sort of match," Muller said.

Nadal said his opponent "played a great game".

"It was not my best match but I played against a very uncomfortable opponent. I did well to come back but made a few mistakes. It was a great feeling to have the support of the crowd, so sorry to them," the Spaniard said.

Up next for Muller is Croatia's Marin Cilic, the No. 7 seed, who rolled over Spain's Roberto Bautista Agut 6-2, 6-2, 6-2 in the round of 16.