MAMARONECK, N.Y. - Winged Foot Golf Club is famous for its "massacre," but the devastation that occurred here Sunday was entirely self-inflicted.

Needing only pars on the final hole to win the 106th U.S. Open, both Phil Mickelson and Colin Montgomerie coughed up double bogeys that handed the major championship to Geoff Ogilvy by a stroke.

"I still am in shock that I did that," Mickelson said of his fourth runner-up finish in the U.S. Open. "I just can't believe that I did that. I am such an idiot. ... I just can't believe I couldn't par the last hole. It really stings."

Mickelson and Montgomerie fell a stroke behind Ogilvy's 5-over-par 285 into a tie for second with 2003 champion Jim Furyk, who missed a 4-footer on the final hole to bogey his own way out of a potential 18-hole playoff. Padraig Harrington spoiled a bogey-free day with three in a row down the stretch to finish alone in fifth place.

But it was Mickelson's collapse that will resonate as much as Ogilvy's victory.

Mickelson's final-hole disaster - which involved the roof of a corporate tent, a tree, a plugged bunker lie and the thick collar of rough - cost the reigning Masters Tournament and PGA champion the opportunity to go to July's British Open at Hoylake with a professional majors sweep on the line.

"This one hurts more than any tournament because I had it won," said Mickelson. "I had it in my grasp and just let it go, as opposed to somebody making a long putt or what have you."

Montgomerie, who did drop a sweeping 60-foot putt on No. 17 to tie for the lead, was equally downtrodden after posting a closing six despite striping a drive down the center of the fairway. After missing his approach short right, he three-putted from 40 feet.

"It's a very tricky hole but it shouldn't be that tricky from the fairway," the Scotsman said after his third U.S. Open runner-up finish. "This is the first one that I've really messed up."

While Winged Foot tortured the field all week despite its fair setup, the riveting closing nine was as much a measure of the individuals playing as it was the difficulty of the course.

Only Ogilvy did what he had to do down the stretch, chipping in for par from 30 feet on the 17th hole and getting up and down for par on the last - the only closing par by any of the top five finishers. That he was standing with the U.S. Open trophy was just as shocking to him.

"I thought I'll get this up and down and lose by a shot," said Ogilvy, the first Australian to win a major since Steve Elkington at the 1995 PGA in a playoff over Montgomerie. "I think I was the beneficiary of a little bit of charity."

If it wasn't vaudevillian, it was certainly Van de Veldian. Mickelson and Montgomerie - who shared the lead at 4 over while bracketing Ogilvy on opposite ends of the 18th hole - chopped up the finish with double bogeys that were no way inflicted by the golf course.

It was reminiscent of the astonishing triple bogey that Jean Van de Velde made to blow a three-shot lead on the final hole of the 1999 British Open at Carnoustie.

Mickelson took a two-shot lead with a short birdie putt on No. 14 and seemed in relative control despite missing every fairway on the back nine.

But he bogeyed No. 16 after plugging his approach in the bunker and parred 17 from the trees, despite his drive landing in a garbage can, to set himself for a chance to par and win.

Hoping to hit his "bread-and-butter" cut driver on 18, Mickelson overcooked it wide left onto the roof of a corporate tent. It bounced into a good lie in the trampled rough, but his iron shot hit a tree flush and bounced back at him. His third shot buried in the left greenside bunker, and his blast out rolled over the green into the thick collar of rough. Needing to chip in to force a Monday playoff, he missed and made the comebacker to tie for second.

"As a kid I dreamt of winning this tournament," Mickelson said. "This one is going to take a little while to get over."

Reach Scott Michaux at (706) 823-3219 or scott.michaux@augustachronicle.com.