Rafael Nadal remains the undisputed 'King of Clay'.

Even the world's top player can't argue that.

The second-seeded Nadal extended his winning streak to 42 matches on clay with a 6-2 6-7 (2-7) 6-3 7-6 (7-5) victory over Roger Federer on Sunday in the final of the ATP Masters Series Monte Carlo.

Federer had 29 straight wins in Masters Series events, but could not take the Monte Carlo title away from Nadal in what was a possible preview of the French Open final next month.

The 19-year-old Spanish lefthander earned the nickname 'King of Clay' after beating Federer in last year's French Open semi-final en route to the Grand Slam title.

"It's been an unbelievable week for me," Nadal said.

"It couldn't have been any better. It is really important to start the claycourt season with a victory here in Monte Carlo and defeat Roger Federer in the final."

Federer is an amazing 130-6 since the 2004 Olympics, but three of those defeats have come against Nadal.

The Swiss superstar is just 1-4 against Nadal, including a 2-6 6-4 6-4 loss in the Dubai final last month.

"All in all, I thought it was a good match," Federer said.

"I enjoyed the battle against him, and it answers a lot of questions I was asking myself prior to the claycourt season. This was definitely a fantastic week for me."

This final was the first matching the top-ranked players in Monte Carlo since number one Ivan Lendl beat second-ranked Mats Wilander in 1985.

It lasted three hours and 49 minutes and featured two tie-breaks - one to Federer and one to Nadal.

Federer held a 3-0 lead in the fourth set tie-break, but Nadal rallied to win five of the next six points and ended the match with a forehand pass that bounced on the line.

Nadal started quickly, winning the first four games.

Federer was quite sloppy on his least favorite surface, committing 24 unforced errors in the first set.

Nadal took the set in 42 minutes, serving out to love as Federer tamely sent another unforced error into the net.

"Today I didn't have a good start," Federer said.

"I had a really tough time getting into the match.

I am not sure why it happened but I have to try to change it next time. Against him I have to play aggressive and it's tough to do that from the beginning."

Nadal produced some extraordinary shots to break Federer's serve in the seventh game of the second set, taking a 4-3 lead.

But with Nadal serving for the set at 5-4, Federer broke back, finally starting to show the form that elevated him to the status of best player in the world.

The set went to a tie-break and Federer took control, winning four of the first five points before closing it out with an ace.

The two traded breaks at the start of the third set and Nadal broke again in the eighth game to take a 5-3 lead.

He closed it out on serve with an inside-out forehand after Federer had saved one set point with a sliced drop shot.

Federer committed 21 more unforced errors in the set compared to 10 for Nadal.

The fourth set looked like a repeat of the first when Nadal broke twice to take a 3-0 lead.

But Federer fought back, breaking in the next game and then again in the eighth to even it at 4-4.

The rivals then held serve until the breaker.

Federer appeared to be on the verge of forcing a fifth set when he took the first three points of the tiebreak, but Nadal came back and won match point on Federer's serve.

"I don't want to think about Roland Garros, my next tournament is Barcelona and my goal is now to do well there," Nadal said. "I look forward to be playing in Spain again."