Retief Goosen held his nerve on a thrilling final day at Shinnecock Hills to claim his second US Open title.
US unless stated
-4 Retief Goosen (SA)
-2 Phil Mickelson
+1 Jeff Maggert
+4 Mike Weir (Can), Shigeki Maruyama (Jpn)
+5 Fred Funk
+6 Robert Allenby (Aus), Steve Flesch
On a day when nobody beat par, the 2001 champion made fewer mistakes than a high-quality chasing pack.
Phil Mickelson seemed to have one hand on the trophy when he birdied the 15th and 16th, but a double-bogey at 17 handed the lead back to Goosen.
The 35-year-old South African then made no mistakes on the last and tapped in for par to claim a two-shot victory.
Leading by two going into the final round, Goosen would have expected his main challenge to come from playing partner and compatriot Ernie Els.
But the world number two was the most high-profile casualty on a day when the United States Golf Association's pin positions and lightning-fast greens definitely held sway.
Els, needing a victory to replace Tiger Woods as world number one, started with a double-bogey and never recovered. He ended up with a ten-over-par 80, one of 28 players in the 66-strong field to fail to break 80 on Sunday.
Woods endured another difficult day, only beating his worst US Open round by one when he birdied the 18th, and was quick to complain about the severity of the Long Island links afterwards.
As Els and the other potential challengers Fred Funk, Jeff Maggert, Shigeki Maruyama and Mike Weir went backwards, the contest soon became a two-horse race between Goosen, who opened with a birdie, and Mickelson.
With the partisan crowd roaring their favourite on, Mickelson appeared to be putting together the kind of back-nine charge that so memorably overhauled Els at the Masters in April.
But a three-putt from within five feet at the par-three 17th stopped the 34-year-old American in his tracks.
Goosen, who had watched Mickelson's lapse from the tee, then found the bunker to the left of the green.
But, with a second major title for each of them on the line, the unflappable Goosen saved his par with a textbook up-and-down.
Mickelson went to the 18th knowing he needed a birdie to apply some pressure but his approach failed to bite on the rock-hard green and he was left with an almost impossible putt for a three.
He missed, despite the best efforts of his vociferous supporters, but made his par to finish the tournament at two under.
Goosen, the only other man in red numbers, promptly found the green with a seven-iron to give himself three putts for victory. He needed only two.
American Jeff Maggert finished third at one-over 281 after carding a 72, with 2003 Masters champion Mike Weir (74) and Japan's Shigeki Maruyama (76) a further three shots back in a tie for fourth.
Spain's Sergio Garcia was the best-placed European at 11 over, but a tie for 20th is a bad return for the 19-strong contingent from across the Atlantic and does not bode well in a Ryder Cup year.