London - Six-time champion Roger Federer recovered from losing the first set to move into the Wimbledon quarter-finals with a 6-7 (5/7), 6-3, 6-3, 6-3 victory over Russia's Mikhail Youzhny on Monday.
Federer made serene progress through his first three matches at the All England Club without dropping a single set, but the third seed was unable to preserve that record against Youzhny on Court One.
The 29-year-old lost the opening set of the match in a tie-break, although he wasn't too concerned about that as he quickly recovered his composure to see off the tenacious 18th seed and set up a last eight clash against France's Jo-Wilfried Tsonga.
Federer, who last won Wimbledon in 2009, has now reached 29 consecutive Grand Slam quarter-finals to extend his Open era record and remains on course to equal Pete Sampras's record of seven Wimbledon men's singles titles.
"It was a tough first set to lose in the end because I was playing well," Federer said.
"To lose the first set in a Slam is tricky mentally. You think: 'Is he going to get a boost and play even better'. It can be quite dangerous so I was pleased to win the second set with two breaks.
"It's always somewhat tricky to play on Court One because I'm not so used to the surroundings, but I was happy with the way I played and I'm looking forward to a tough battle with Tsonga."
Youzhny had lost all 10 of his meetings with Federer and hadn't even won a set in their last six encounters, a miserable record which suggested there was little hope of a belated birthday present for the Russian, who turned 29 on Saturday.
History proved an astute guide in the end, but it took a while before Federer stamped his authority on the match.
Federer's serve has been a thing of beauty throughout the tournament, yet Youzhny has a dangerous delivery of his own and neither man could find a chink in the others' armour as the first set went to a tie-break.
Federer took a 4-2 lead in the breaker, but he then surrendered the initiative to hand Youzhny two set points.
The Swiss star saved one but a miscued slice on the next gifted Youzhny a shock one-set lead.
That indignity drew a typically forceful response from Federer. He teased and tormented Youzhny from the baseline before breaking for a 3-2 lead with a sliced drop-shot that left the Russian tangled up with the net as he lunged in vain for the ball.
Federer's equilibrium was restored and he began to unload some searing ground-strokes, breaking again at 5-3 to clinch the second set.
A brilliant backhand down the line gave Federer break-point in the opening game of the third set and Youzhny's tame double-fault conceded the break.
Another Federer break opened up a 4-0 lead and he soon moved two sets to one ahead.
Faced with Federer's vast arsenal of shots, Youzhny gamely refused to wave the white flag.
Despite his gutsy defiance, he was still powerless to stop the 16-time Grand Slam winner going through after he broke early in the fourth set.