By Piers Newbery
BBC Sport at Wimbledon
Roger Federer showed glimpses of his best form and flashes of nerves as he beat Juan Carlos Ferrero on Centre Court to reach the last eight.
The top seed took control in game four, when a Ferrero forehand error gave him the break and ultimately the set.
Federer really found his rhythm in the second, and another Ferrero forehand mistake gave up the break in game five.
But Federer was broken when serving for the match in the third and needed a tie-break to win 6-3 6-4 7-6 (8-6).
In a high-quality match, Ferrero showed that he is well on the way to regaining the form that made him world number one two years ago.
But after struggling with his forehand early on, Federer - who had been a little below par in the first week - moved up a gear in the second set.
Ferrero looked capable of prolonging the match in the third as Federer was content to rally from the baseline.
However, two break points passed the Spaniard by in game eight and Federer grabbed what appeared to be the decisive break three games later.
He then played a woeful service game and started the ensuing tie-break with a wild drive-volley, but recovered his nerve to edge to victory.
"I think I had to play a really solid match," said Federer.
"It was pretty good. I got the early break and I served all the way through pretty solid apart from the last game.
"I'm quite happy. He played tough off the baseline, especially in third."
And the champion admitted he did feel nerves when failing to serve out the match at the first attempt.
"The pulse goes higher and I definitely feel the pressure in those moments," he said.
Ferrero admitted that Federer has hit form at the right time.
"He played so good," said the Spaniard. "He's playing with lots of
confidence and no mistakes and holds his concentration all the time."
Federer now takes on Fernando Gonzalez, who continued his best-ever run at Wimbledon by beating Russia's Mikhail Youzhny.
The heavy-hitting 21st seed delighted the large Chilean contingent on Court Three with a 7-6 7-6 6-3 win.