By Piers Newbery
BBC Sport at Wimbledon
Top seeds Roger Federer and Rafael Nadal continued their progress through the Wimbledon draw with fourth-round wins on Monday.
Federer is going for his fourth successive Wimbledon title
Defending champion Federer hardly broke sweat on a sweltering Centre Court as he won 6-3 6-3 6-4 against Tomas Berdych in one hour 23 minutes.
And Nadal was equally impressive in beating Georgia's Irakli Labadze 6-3 7-6 (7-4) 6-3 on Court One.
Federer meets Mario Ancic next, while Nadal takes on Jarkko Nieminen.
World number one Federer broke Berdych's serve in game seven and, apart from saving a break point at the start of the second, was completely untroubled by the Czech 13th seed.
But he later insisted: "It was an awkward match - Tomas was obviously struggling with a shoulder injury.
If Nadal made the final that would be quite a surprise
"I cannot say it was my best match. The first two rounds were better. I knew from the first second I was through and just had to wait for the break to come.
"I thought I was the better player, but I have been tested."
And after clay-court king Nadal reached the quarter-finals on Wimbledon's grass for the first time, Federer considered the prospect of facing the Spaniard in Sunday's final.
"Obviously it will be interesting on grass, we still don't know how good he is," said Federer, who has lost six of his seven matches against the French Open champion.
I've achieved my goal because I'm not playing bad on this surface
"He's had a pretty good draw, even though Andre (Agassi) is a pretty tough player.
"If he made the final that would be quite a surprise to many, even though he's such a good player that you could expect him to do that.
"It would surprise me to a certain degree."
Nadal coped well with the hard-hitting Labadze, ranked 166, breaking him early to take the first set and fighting back from a mini-break down to take the second set tie-break.
As pumped up as ever, the Mallorcan kept up the intensity in the third set as his opponent wilted, wrapping up victory in two hours 12 minutes.
"It's very important for me to be in the quarter-finals," said Nadal. "You can see in the history it's been very difficult for Spanish players.
"I didn't think that (I would get this far) before the tournament.
"Now I know I'm playing a very, very good tournament. I've achieved my goal because I'm not playing bad on this surface."