'My motivation is to be back to that level but I don't know if I can'

It was a clearly deflated Rafa Nadal who admitted he has no idea whether he can ever reproduce the form that helped him win two Wimbledon titles after maverick Dustin Brown inflicted a fourth successive embarrassment.

Nadal's Wimbledon triumphs in 2008 and 2010 now seem an age ago and his record since 2011 has been blotted by four losses to players ranked 100th or lower.

Brown was the latest low-ranked opponent to come out hitting against Nadal at the All England Club, seizing the moment by attempting to knock the Spaniard out of his comfort zone.

The German with a Jamaican father was far from one-dimensional and mixed up ferocious hitting with clever drop shots and surprise charges to the net.

But Brown, like Nadal's three previous conquerors Lukas Rosol, Steve Darcis and Nick Kyrgios, would probably have received short shrift had they played the Spaniard when he was at his Wimbledon-winning peak.

"I don't know if I will be back to the level of 2008 or 2010 or 2007 or 2006 or '11," Nadal told reporters after his 7-5, 3-6, 6-4, 6-4 defeat.

"My motivation is try to be back to that level. But I am going to keep working on that. But if I don't make that happen," he added tailing off before reminding people that he is a five-times Wimbledon finalist.

It was always going to be a hard task for Nadal, 14-times grand champion, to buck the recent trend and clinch a third Wimbledon title this year.

His indifferent form dropped him to 10th in the world, his lowest ranking in over a decade, and he was likely to have to beat the world's top three in Novak Djokovic, Roger Federer and Andy Murray to win the tournament.

Wimbledon's slick grasscourts have also provided the perfect medium in recent seasons for players to upset Nadal's baseline rhythm and Brown made the most of his chance.

Harking back to a previous era, Brown relentlessly served and volleyed, following his delivery into the net 99 times in the match and winning the point on 71 occasions.

"This court gives the possibility to these kind of players to play like this, with chances of success," Nadal said.

"I didn't serve good enough.

"After losing the first set, you are under pressure for the rest of the match. That's it."