But there is one more round to go before the Swiss and the Spaniard meet in what would be a dream final on Sunday.

Federer must first vanquish the strapping Marat Safin, himself a former world No 1, whose talent has long done battle with a tortured soul.

Safin, the world No 75, noted the irony of regaining his form on Wimbledon's lawn, having famously groused years ago that 'grass is for cows'.

But Wimbledon has represented a renaissance for Safin, 28, who advanced to today's semifinals by defeating his fourth consecutive seeded opponent, Feliciano Lopez, 3-6, 7-5, 7-6 (7-1), 6-3.

Federer, who dismissed Mario Ancic 6-1, 7-5, 6-4 on Wednesday, has beaten Safin eight times in 10 meetings and has not lost on grass in six years and 64 matches.

But he will also remember that when Safin clinched a shock Australian Open title in 2005, it was his title that the Russian took, courtesy of a dramatic 5-7, 6-4, 5-7, 7-6 (8-6), 9-7 win in the semi-final.

'I never look at Marat as a 75 in the world,' said Federer. 'That's ridiculous, and he knows that himself. He's showing again what he can do.'

Safin, who scalped world No 3 Novak Djokovic in the second round, said: 'I'm surprised I'm still here. But this is my first semi-final here.

'To beat Federer, you need to be like Nadal and run around like a rabbit and hit winners from all over the place.'

The only certainty about Nadal's next opponent is that he will be unseeded, at least 30 years old, and woefully outmatched.

The remaining quarter-final, pitting Germany's Rainer Schuettler, 32, against Arnaud Clement, 30, resumed yesterday after being delayed by rain on Wednesday - before rain halted play again.

It deprived the winner of a full day's rest before facing Nadal.

ASSOCIATED PRESS

Wimbledon: Day 12
Live, Ch24, 6.30pm