Wayward driving from Paul McGinley handed Michael Campbell a 2&1 victory in the final of the World Match Play.
The pair had staged a superb see-saw contest for most of the day, Campbell taking a one-hole lead to lunch.
The New Zealander forged three clear soon afterwards, finding his putting touch just as McGinley's deserted him.
And, although Irishman McGinley fought back to level after 27, he duffed shots into the trees at 15 and 16, gifting Campbell a memorable Wentworth win.
The winner's cheque for £1m is the latest prize in a breakthrough year for Campbell, who won his first major at the US Open in June.
But he was made to work very hard by the popular McGinley, who enjoyed the majority of the crowd support.
It was McGinley who made the perfect start to the final, sinking a 15-foot par putt at the first.
He was soon pegged back and that became the pattern of the morning's play, neither golfer breaking clear until Campbell started quickly after lunch.
The New Zealander rattled in from 20 feet at the first and also won the fourth hole to pull three clear.
Stubborn McGinley replied with birdies at six and seven and levelled again before the turn before the pressure began to tell on both golfers.
The tension was briefly broken at the 11th green when a female streaker put in an appearance.
And McGinley looked favourite to prevail on the 15th tee, but he made a mess of his second shot to fall one hole behind.
The Irishman then drove wildly into the trees on 16 to effectively seal his demise, Campbell halving the 17th to win.
"There was a different tension here to what I felt at the US Open," said the champion.
"Paul was such a tough competitor and I knew if I backed off he would take advantage. But, fortunately, I managed to stumble over the finish line."
Campbell attributed his win at the World Match Play to a radical life overhaul.
"I had a look in the mirror, changed my 'Cambo' team and worked on different aspects of my life, not just golf," he said.
McGinley declared himself "hurt like you can't imagine" after losing.
"I fought as hard as I could and I'm bitterly disappointed," said the Irishman, who has not won an individual title since 2001.
"I desperately need to get over the finishing line again.
"Every time I hit a four-iron I hit a crap shot," said McGinley, who indicated that he was going to get the offending club checked out.