London: Holder Roger Federer produced an hour of sublime quality to crush Rafa Nadal 6-3 6-0 at the ATP World Tour Finals on Tuesday and clinch a place in the last four with a match to spare.   

The 17,500-capacity crowd crammed into the O2 would have expected something longer from the eagerly anticipated 26th clash of the great rivals but the 60 minutes of magic Federer served up will live long in their memories.   

Firing winners to all corners of the court, the Swiss 16-times grand slam champion was simply unstoppable as he recorded his most emphatic victory against the man who had beaten him in 17 of their previous encounters.   

"This win ranks high because it's against my biggest rival, probably," Federer told reporters. "It was a great match for me from start to finish. I've felt the power of Rafa in the past, so this is a great match for me, a nice win."   

World number two Nadal now faces a win or bust clash with Jo-Wilfried Tsonga on Thursday in his final Group B match after the dangerous Frenchman Tsonga produced fireworks of his own to beat American Mardy Fish 7-6 6-1 and stay in contention.   

Federer's dazzling display softened the blow for the home crowd and organisers after Andy Murray withdrew from the blue-riband tournament when his superb season was cut short by a groin injury.   

Murray, the world number three, announced that he was pulling out after aggravating the injury during his opening Group A defeat against Spain's David Ferrer on Monday.   

Serbia's world number nine Janko Tipsarevic, the on-site alternate, will take Murray's place for the remaining matches in Group A and will get to play his compatriot Novak Djokovic.   

There was something of a novelty value about that match as it was the first time the two dominant players of the last decade had met with neither at number one in the ATP rankings and the first time they had met in a round-robin match.   

Glum Murray   

Federer trailed 17-8 in their head to head record but had won all three previous meetings indoors, including last year's final at the O2, and once again the court proved perfect for his game as winners flowed from his strings like liquid gold.   

There was no real hint of what was to come as the first five games went with serve, although the pace and precision of Federer's groundstrokes was ominous for Nadal.   

Federer, who is bidding for a record sixth title at the tournament in three different cities, took charge in the sixth game when he won a sensational 33-shot rally on break point to lead 4-2 and from that moment on never looked back.   

He needed just 32 minutes to seal the first set and, try as he might, Nadal was powerless in the face of the onslaught as Federer swept to a victory every bit as ruthless as Nadal's thrashing of the Swiss in the 2008 Roland Garros final when he offered up just four games in three sets.   

"We've played so many times, sometimes it just derails for you, like it derailed for Rafa today and it did for me at the French Open," Federer said, offering some sympathy for the Mallorcan. "You know what good front-runners, the top guys are.  Once you start rolling, it's hard to stop the player.   

"Next thing you know, you're facing a debacle."   

Nadal, winner of 10 majors but never the season-ending title, can still redeem himself although Tsonga will fancy his chances after a convincing display against weary debutant Fish who can no longer reach the semis.   

Fish fought hard to get back into the opening set, breaking Tsonga when the powerful Frenchman served at 5-4, but the tiebreak proved crucial.   

Tsonga, sporting a pair of bright red tennis shoes, took it and despite dropping serve immediately in the second set he then  reeled off the next six games in swashbuckling fashion.   

Federer still tipped Nadal to progress, however.   

"You can never count out Rafa," he said of the match which has now become a tradtional knockout. "It's an open match to a degree but I still favour Rafa because of who he is."   

Murray can only rest and start preparing for next season after a long season in which he reached the semi-finals of all four grand slams and won five titles finally caught up with him.   

"It was one of those things where you kind of hope that things are going to get better, but the reality was that wasn't ever going to happen," a glum-looking Murray told reporters.   

"Yesterday I was really unhappy on the court. I wasn't enjoying it at all. I couldn't give anywhere near my best."   

World number one Djokovic seeks his second Group A victory on Wednesday against Ferrer, while Tomas Berdych, who lost a tight three-setter to Berdych on Monday, faces Tipsarevic who will be making his debut in the elite event.