MONTE CARLO (AFP) - Rafael Nadal won an historic fourth successive Monte Carlo Masters title on Sunday as he defeated world number one Roger Federer 7-5, 7-5 in the latest instalment of their epic rivalry.

The 21-year-old triple French Open champion came back from 0-4 down in the second set to achieve his third final victory in a row over Federer in the principality and his 22nd successive win in the tournament.

It was also his ninth win in 15 career meetings with the world's top player and his seventh in eight claycourt clashes.

The last man to win four Monte Carlo titles in a row was New Zealand's Anthony Wilding in 1914 but Nadal, who now has 24 career titles, is the first man to complete the feat in the Open era.

"It's hard to imagine winning this title for four years in a row," said Nadal.

"But Roger played a great match. We always have good finals."

Federer was full of praise for his opponent.

"I have to congratulate Rafa. It seems to be the same thing every year here," he said.

"He played great but I have to be happy with my tournament especially since I could have lost in the first round.

"It was a tough match. I played OK but I'm disappointed that I let him back into the match. But he deserves to win - he's a hell of a claycourt player."

Federer, who was laid low by glandular fever in January and lost his Australian Open title, said he was taking positives from the match.

"I've come back strong and I'm happy where things are right now. It's been a postive week for me. I could have lost in the first round. But I've beaten some great players here and pushed Rafa today.

"I know I can beat him if I play the right way - I didn't have that feeling when I played here last year. I'm healthy and moving well."

The two great rivals shared breaks in the first two games before the top seeded Swiss nipped ahead to lead 4-3, when Nadal, off balance, could only send a lob long.

However, the 21-year-old Nadal retrieved the break, helped by a fortunate net cord which wrong-footed the advancing Federer, to pull level at 4-4.

Nadal was now in the ascendancy and created two set points in the 12th game when Federer unleashed a sloppy backhand.

The set was the Spaniard's after 51 minutes when he met a deep Federer volley with a sliced backhand of his own.

Federer, who had been within two points of a shock defeat in his opening match against another Spaniard, world number 137 Ruben Ramirez Hidalgo, broke Nadal in the first game of the second set and backed it up with a hold to lead 2-0.

In a topsy-turvy final, the 12-time Grand Slam title winner broke again to lead 3-0, held for 4-0 but then allowed his opponent to hit back to 4-4 on the back of two breaks of his own.

Both men then held on but Federer cracked in the 12th game and handed Nadal the title with a loose backhand.

The statistics told a depressing tale for Federer in the 1hr 43min final where he sent down 44 unforced errors to Nadal's 20.