Mickelson's try for a third straight major championship ended in collapse Sunday at Winged Foot when he double-bogeyed the 18th hole to all but hand Australian Geoff Ogilvy the win.

"I still am in shock that I did that. I just can't believe that I did that. I'm such an idiot," Mickelson said afterward, looking nothing but shell-shocked.

Ogilvy chipped in for par at 17, made par from a sand divot on 18 and closed with a two-over 72 to become the first Australian in 25 years to win the U.S. Open.

He celebrated in front of a television monitor, having finished one group ahead of Mickelson.

"Just to hang on the way I did, to finish the way I did -- yeah, I don't really have the words," said Ogilvy, who earned $1.225 million for the win.

Ogilvy's five-over-par 285 winning score was the highest since Hale Irwin's seven-over at Winged Foot in 1974 -- the so-called "Massacre at Winged Foot."

Sunday, it was good for a one-shot win over Mickelson (74), Jim Furyk (70) and Colin Montgomerie (71) -- who all stumbled down the stretch, sharing in their own massacre.

But it's Mickelson's collapse that will go down as one of the worst in U.S. Open history, if not major championship history.

Looking to become just the third player ever to win three consecutive majors, Mickelson hit only 2-of-14 fairways in his final round. His last two misses were bizarre: into a trash can at the 17th hole, and off a large, white tent at the 18th.

While he made par after a drop at 17, Mickelson played the par-four 18th like the Mickelson who was called "The Best Player Never to Win a Major" before he claimed three of them.

Mickelson's second shot on 18, which hit a tree, will be questioned for years. Getty Images

His third shot stuck deep in a greenside bunker. His fourth rolled over the green into the rough on the other side.

A miracle 30-foot chip for bogey would have forced a playoff, but Mickelson skipped the shot past the hole and ended with his only double-bogey of the tournament.

This after the world's No. 2 golfer said players at Winged Foot didn't need to avoid bogeys. They needed to avoid double-bogeys.

"I came out here and worked so hard, so many days, hadn't made a (double) bogey all week, and then (double) bogeyed the last hole," said Mickelson.

New York-area fans have seen Mickelson come close to U.S. Open glory before, sitting through runner-up finishes to Tiger Woods at Bethpage Black in 2002 and Retief Goosen at Shinnecock in 2004.

"I feel for Phil. I know he was the hometown favorite to win. But he's won a few majors recently, so I can gladly take one away," said Ogilvy, the first Aussie to win a major since Steve Elkington at the 1995 PGA Championship.

Mickelson broke through with a win at Augusta two years ago, then won the 2005 PGA Championship and this year's Masters. In majors on U.S. soil, it's the U.S. Open that's eluded him.

"As a kid, I dreamt of winning this tournament," said Mickelson, who also finished second to the late Payne Stewart in 1999. "I can't believe it. Even a bogey would have gotten me into a playoff. I just can't belive I did that."