Federer held his nerve to win despite an unconvincing display
World number one Roger Federer survived a huge scare against Spanish qualifier Ruben Ramirez Hidalgo to stumble into round three of the Monte Carlo Masters.
Spain's world number 137 Hidalgo looked to be on the verge of a shock win at 5-1 and 30-15 up in the deciding set.
But Federer, fresh from his Estoril Open success, won five straight games to force a tie-break, which he took to seal a 6-1 3-6 7-6 (7-1) victory.
Second seed Rafael Nadal, meanwhile, eased past Mario Ancic 6-0 6-3.
The Spaniard, bidding for a fourth consecutive title in the principality, never let Croatian Ancic into their match, winning the first eight games on his way to victory in 75 minutes.
He next faces compatriot Juan Carlos Ferrero, who beat Finn Jarkko Nieminen 6-3 6-3, while Federer meets Frenchman Gael Monfils, who beat Croatia's 15th seed Ivo Karlovic 7-6 (10-8) 6-1.
"I felt a bit slow out there," said Federer. "He played so badly in the first set that he almost faked me out but when he served for the match it became tough on him.
"I'm disappointed by the way I played. I could have lost but I got through and it's six matches and six wins on clay so I'm happy."
Federer, who was given a first-round bye, twice came within two points of defeat on his Spanish opponent's serve.
The 12-time Grand Slam winner was not helped by 55 unforced errors in the match, but his greater experience told as he held his nerve, finally clinching victory in the tie-break when Hidalgo hit a forehand long.
It has been a year of under-achievement so far by Federer's usual standards after three semi-final finishes and a quarter-final exit in Miami.
And after spraying groundstrokes long and wide and looking shaky on serve for long periods against Hidalgo, he will have to up his game if he is to add to his 54 career singles titles in Monte Carlo.
Elsewhere, Russian fifth seed Nikolay Davydenko overcame a second-set blip to beat Italian Simone Bolelli 6-2 7-6 (7-5).
Davydenko, who pulled out of the Estoril Open final against Federer with a leg injury, said: "I didn't feel any injuries, my legs were OK."
Spain's fourth seed David Ferrer eased into the third round with a 6-2 6-3 victory over Russian Marat Safin, while David Nalbandian, seeded sixth, beat Belgian Olivier Rochus 6-4 6-3 to secure his progress.
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