Roger Federer won his third Grand Slam title of the year as another awesome display of tennis saw off Lleyton Hewitt in the US Open final.

Federer produced some sparkling shots to destroy Hewitt 6-0 7-6 (7/3) 6-0 on the Arthur Ashe Stadium at Flushing Meadows.

Only a brief slip in Federer's quality in the second set prevented an even greater margin of victory.

As it was, it was still the most one-sided US Open final for 30 years.

The victory also meant Federer became the first player since Mats Wilander in 1988 to win three legs of the Grand Slam in a calendar year.

Afterwards Federer admitted: "I don't know if I can play any better.

"I can't believe I've done this year so great - three out of four - and now to win the US Open, it's incredible.

"The key was the end of the second set which was very close. Luckily for me I played a good tie-breaker and could take the title in the third set."

Hewitt paid tribute to his rival's performance.

He said: "It's an incredible effort what he's done the whole year with the depth in men's tennis these days.

"I don't think people realise how hard it is to win three major titles in a year."

Federer came into the match as a hot favourite to add to his Australian Open and Wimbledon crowns and only for a few games in that second set was there any doubt that he would do so.

He simply blitzed Hewitt in the opening set, restricting his opponent to just five points in the 18 minutes it lasted.

His superb shot-making was superior to the 2001 champion's as he produced more power and greater depth to leave his 23-year-old rival stunned.

It was not until he was 6-0 2-0 down that Hewitt - who had come into clash on a 16-match winning streak and having not dropped a set in New York - won a game, letting out a roar of delight as he did so.

Federer's level dropped slightly after that as Hewitt threatened his serve for the first time.

He missed two break points during the middle of the set but when Federer stepped up to serve for a two-set lead, the fourth seed finally made the breakthrough.

In an epic 10th game, Hewitt missed three break chances and Federer blew three set points before the Aussie levelled the set up at 5-5.

A tie-breaker followed, but that was where the mini-crisis for the tournament favourite ended.

Hewitt quickly fell 4-0 down and although he got it back to 5-3, Federer took the breaker by seven points to three to move within touching distance of the trophy.

This time he didn't let up, instead putting the foot back down on the gas to romp away with the third set.

Federer clinched the title on his second match point, poignantly with a forehand winner, before collapsing in delight to the court floor.

He is the first man in the Open era to win his first four Grand Slam finals and after a performance like this you wonder how many more will follow.