Swiss player Roger Federer mops his brow during his clash with Frenchman Jo-Wilfried Tsonga during their quarterfinal match at Wimbledon on Wednesday. Federer was defeated 3-6, 6-7 (3), 6-4, 6-4, 6-4. Leon Neal / Agence France-Presse

Six-time Wimbledon champion Roger Federer believes he is still a Grand Slam contender despite suffering a second successive quarterfinal loss at the All England Club.

The former world No 1slumped to a dramatic 3-6, 6-7 (3), 6-4, 6-4, 6-4 defeat to France's Jo-Wilfried Tsonga on Wednesday, shattering his hopes of equaling Pete Sampras's record of seven Wimbledon titles for another year.

But even with his 30th birthday approaching in August, Federer is adamant he can add to his Grand Slam collection of 16, the last of which came at the Australian Open in 2010.

"I think I definitely can, yes. I wouldn't be here if it wasn't the case," said the Swiss. "I think I'm playing well. I thought my game was plenty good enough this year to win the tournament. Unfortunately, there's only one that can win it, and the rest go home empty-handed.

"I'm healthy. Even though I took a tough loss today, I don't feel discouraged in any way. I'll work harder than ever and hopefully come back extremely strong for Davis Cup next week and then the American summer again."

Wednesday's defeat was the first time Federer had lost a Grand Slam match from being two sets to love up.

He previously boasted a 178-0 Grand Slam win-loss record when winning the first two sets.

His only defeats from two sets to love up had come against Lleyton Hewitt in the 2003 Davis Cup final and in the 2005 Masters Cup in Shanghai against David Nalbandian.

"Is it easy for anybody at the moment? I don't think so," said Federer as he reflected on the strength of the men's game. "I think it's pretty tough for anybody right now to win Grand Slams."

Federer, whose last Wimbledon title came in 2009 in an epic five-set duel with Andy Roddick, insisted he is not obsessed by beating good friend Sampras's record of seven Wimbledon titles.

But he knows that with defending champion Rafael Nadal being almost five years his junior, the task is becoming harder.

"I love equaling any record Pete has made, but it's not the driving force behind my motivation," said Federer. "Look, I love Pete. It's always nice doing stuff that he did. But at the end of the day I'm trying to win a tournament."

On Wednesday, there were no signs of the drama to come as Federer, who went into the match with a 4-1 record over 12th seeded Tsonga, was in majestic form early on.

He cruised through the first set on Centre Court courtesy of a break in the second game, which turned out to be his only break of the dramatic afternoon.

Tsonga, playing in his second successive Wimbledon quarterfinal, was more solid in the second, but buckled in the tiebreak which Federer was never going to relinquish once he had taken a 5-1 lead.

But then Federer's world turned upside down.

He was broken in the third game of the third set, the third of the fourth to help level the tie before a single crucial break in the first game of a one-sided decider.

"I played too good. It wasn't a shocker second-round loss in straight sets, some stupid match I played. It was a great match from both sides," said Federer.

"To talk bad about this match would be unfortunate. I really did play well, and I also thought Jo played an amazing match, as good as I've seen him play for such a long period of time."