By Martyn Herman

LONDON (Reuters) - Frenchman Jo-Wilfried Tsonga shredded the Wimbledon script with a devastating fightback to knock six-times champion Roger Federer out on Wednesday and clinch a semi-final showdown against Novak Djokovic.

Federer's unlikely 3-6 6-7 6-4 6-4 6-4 capitulation on a stunned Center Court was the first time he had lost a grand slam match from two sets up and meant there would be no repeat of the repeat of the semi-final line-up at the French Open in which the world's leading quartet faced off.

The other usual suspects will be present although defending champion Rafa Nadal had painkilling jabs to numb the pain of a mystery foot injury before a 6-3 6-3 5-7 6-4 defeat of American Mardy Fish to set up a repeat of last year's semi-final against Briton Andy Murray.

Fourth seed Murray, who also lost to Nadal in the French Open semis this month, outclassed unseeded Spaniard Feliciano Lopez 6-3 6-4 6-4 to the delight of the Center Court crowd dreaming of a first British men's singles winner for 75 years.

Federer's defeat in the quarter-finals for the second consecutive year came completely out of the blue.

The first two sets resembled nothing more than a light sparring session for Federer as he went through his silky repertoire to build a commanding lead.

"I felt so good on the court. I was quick. I was just perfect today," Tsonga told reporters after only his second comeback from a two-set deficit. "Every time I was feeling like a dream."


A strangely distant Federer seemed resigned to his fate as Tsonga roared past him and he was sanguine despite a defeat that raises question marks about his ability to add to his record haul of major silverware.

"Except the score, many many things went right," Federer, who played better than he did in last year's quarter-final defeat by Tomas Berdych, told reporters.

"I thought I played a good match myself. I'm actually pretty pleased with my performance today. It's kind of hard going out of the tournament that way, but unfortunately it does happen sometimes."

For a player who won his first 41 matches of the year Djokovic looked vulnerable against Australian upstart Tomic who chipped away at the Serb's confidence with clever play that made a mockery of his 18 years.

After an understandably nervy start to his first grand slam quarter-final he settled down and had plenty of chances to produce another massive shock before Djokovic's greater experience helped him to a 6-2 3-6 6-3 7-5 victory.

"You can say that we had kind of waves throughout the whole match where I played better in the first, nine, 10 games, then he played better," Djokovic, who reeled off seven games in a row to regain control midway through a tricky tactical match, told reporters.

"Very happy to be in semi-finals, first thing, but my foot is not fine," the 25-year-old told reporters after a relatively comfortable win over the American number one.

"But we are in quarter-finals of Wimbledon. Is an emergency, so I had to play," added Nadal, who said the anaesthetic had numbed his foot for five hours.

"I am not scared because I know I have to try my best for the rest of the tournament. That's what I gonna do. And I'm ready to play."

Left-hander Lopez was the last player to beat former British No.1 and three-times semi-finalist Tim Henman at Wimbledon but he was never in with a chance of ending world number four Murray's hopes.

The women return to the spotlight on Thursday when Maria Sharapova takes on Germany's Sabine Lisicki in the semi-finals and Petra Kvitova plays Victoria Azarenka.

(Editing by Ed Osmond)