World number one Roger Federer produced another masterclass in serving to sweep aside David Ferrer 6-2 6-3 6-2 in straight sets and claim his fourth Masters Cup crown in five years.

The legend was unstoppable on his serve, holding on 12 occasions out of 12 and fighting for a break on almost every Ferrer service game.

He won six breaks in total, two in each set - including the final one of the tennis season - to underline his dominance of the men's game and potentially take his 2007 earnings to over $10 million.

"I'm so happy," he said afterwards. "This is the year-end tournament championships and only the best make it through.

"For me to win it again is fantastic.

"Congratulations on a great year to David. Well done to David's team - it's a long year and hopefully we will see you again next year."

Federer came out of the blocks like a train. Had Ferrer harboured ambitions of fighting for the first set to the death - as indeed he should given his form in this Masters Cup - they were blown away inside 20 minutes.

Federer raced 30-0 up on Ferrer's serve and would have had three break points if his challenge against an out call had been successful. It was not and the Spaniard fought back to hold and take the lead.

The Swiss attacked on his serve to hold then broke for the first time in the match. He gained the chance by saving deep in the right corner with a delicate lob that forced Ferrer back and when he reached the ball, Federer was at the net to volley.

Federer was as lethal on his service as he was against world number two Rafael Nadal in the semi-final. Ferrer could not get a look in when the world number one had the ball in his hands and gave up another of his own service games to go 4-1 down.

Federer's third ace won him the sixth game of the set and he looked capable of taking it 6-1 despite going 40-0 down in the seventh, Ferrer struggling with the length on his forehand.

The latter found enough to close it out for 5-2 before Federer executed another love game for the set.

Ferrer started the second set with a hold but was undone yet again on Federer's service as his drives repeatedly went long. In the third game of the set he found the confidence to match his illustrious rival's strokeplay but his errors continued.

A clinical pass won him that game, yet the determination of Federer while saving is daunting in itself and almost took it from him. With the fight fresh in his mind he again faced Federer's serve - and once again he submitted to it, albeit because of a pair of clinical backhands that flashed his way.

Ferrer continued to impress on one point then throw away the next as he held, unsuccessfully challenged Federer's serve then went break point down.

One flat winner in particular showed his ability to impose himself upon the rally, but he could not save his serve when it mattered, thumping one long and wide to gasps from the crowd.

Another Federer ace closed out a love game for 5-3 and he broke on his third chance for the set. The exchanges contained one of the best rallies of the year, ending with a cross-court backhand from Federer that landed right on the line.

The Spanish number two won two break points in the first game of the third set but Federer, as is so often the case, held his nerve to save them both before holding. The score became 1-1 thanks in part to a brilliant Ferrer lob, only for Switzerland's finest to move back ahead.

The crucial moment of the final set arrived when, at break point down, Ferrer failed to volley with conviction and gave Federer the chance to dive across and send back an improbable forehand. Ferrer could not react at the net and volleyed out.

For there until the final game the serve dominated. Ferrer should have won another game at the last, but with the score at 40-15 in his favour, Federer played a backhand winner and excellent volley for deuce.

A double fault exposed the Spaniard's nerves and Federer secured another successful chapter in the remarkable story of his career with a winner that left Ferrer standing.

In 2007 Federer won three Grand Slams, taking his total to 12. He previously won the Masters Cup in 2003, 2004 and 2006.

Jonathan Symcox / Eurosport