Roger Federer produced an outstanding performance to beat Lleyton Hewitt and win his first US Open title.
The world number one was at times unplayable and withstood a Hewitt fightback to win 6-0 7-6 (7-3) 6-0.
Hewitt came into the final on a 16-match winning streak but Federer took control with a stunning first love set.
Hewitt battled superbly in the second but faltered in the tie-break, and Federer powered through the third for his fourth Grand Slam title.
Federer becomes the first man in history to win his first four Grand Slam finals, and the first man since Mats Wilander in 1988 to win three Grand Slams in a year, following victories in Australia and at Wimbledon.
"I'm very happy, I still can't believe what I've done this year," said Federer.
"It's always very important to play well in the finals, in the matches that count, and to win the first set 6-0 was a perfect start."
Federer had beaten Hewitt on his way to taking both Grand Slam titles this year but the Australian had looked stronger than ever in New York, reaching the final without dropping a set.
A tight match had been expected but Federer came out in blistering form, dominating with his forehand and racing through the opening set in 18 minutes.
Another break followed at the start of the second set and a rout looked on the cards, until Hewitt finally got off the mark in game nine.
The Australian is the best fighter in the game and saved three set points on his way to breaking back at 5-5, but Federer regained the initiative early in the tie-break and never looked back.
Hewitt had nothing left in the third and dropped serve three times, as Federer claimed another landmark win in his already remarkable career.
"It's an incredible effort what he's done, to win three Grand Slams out of four," said Hewitt afterwards.
"With the depth in men's tennis the way it is, I don't think people realise how hard it is."
The next goal for Federer must be to complete a Grand Slam in 2005, but he is not ready to contemplate that feat quite yet.
"I don't know if I can play any better," he said. "I'm very tired right now and I don't even want to think about four out of four.
"It's all about partying and relaxing right now."