Such a shot could well have created doubts for his playoff opponent and the eventual winner Keegan Bradley but it is clear that Bradley is a young man who is not easily fazed. He followed Dufner's shot with an even more impressive shot of his own and set the tone for the playoff which he would win by one shot.
The three holes cumulative score playoff saw Bradley birdie the first, par the second and third and when Dufner could not convert his 8 foot putt at the first hole and then three putted the second it was all but over. In a brave bid to keep things alive Dufner somehow managed to birdie the hole that had caused carnage all week, the 18th, but by then it was too little too late.
Keegan had already shown his capacity to remain cool under fire when he bounced back from what appeared at the time to be a tournament ending triple bogey at the par three 15th with brilliant birdies at the 70th and 71st holes to get within one of Dufner who was beginning to experience his own battles.
It was always on the cards that the final few holes of the Atlanta Athletic Club would decide the outcome of this tournament. The stretch of four holes from the 15th to 18th is perhaps the most difficult in championship golf, an accident waiting to happen at every turn.
Dufner will agonise over those dropped shots over the closing stages of regulation play. With four holes to play he had briefly established a five shot lead and seemed unflappable as he was not only finding fairways and greens but the was doing so with apparent ease.
The first real chink in what seemed at the time his impenetrable armour came at the 15th when his hybrid from the tee found the water. He seemed oblivious to the potential damage it might have done when he calmly rolled in a 12 foot bogey saving putt and retained a comfortable margin.
Standing on the tee at the 16th hole, Dufner was still four ahead but up on the green Bradley was making birdie and a few minutes later when Dufner found the greenside bunker and took bogey the difference was just two over Bradley and Anders Hansen.
Bradley's tee shot at the 17th finished 40 feet right of the hole but he hit perhaps the most perfect putt of his career to date and when it is over it might just be that he considers it to be the best putt he ever hits. The ball ran over the gentle tier in the green and picked up speed as it headed towards the hole. It found the centre of the cup and back on the tee Dufner's seemingly easy task had just become that much harder.
Dufner found the green with his tee shot at that same 17th hole but three putted and now all of a sudden the onus was on him at the last to save victory from the jaws of defeat. Ahead Bradley had brilliantly two putted from 50 feet and so now it was Dufner's tournament to lose. He hit a good second to 60 feet however and would also two putt to force the event into extra time.
As Dufner's co 54 hole leader Brendan Steele fell quickly from contention Dufner never relinquished the lead on day four until the first hole of the playoff. He moved two clear at the turn and although Bradley would draw level when he eagled the 12th, Dufner followed with a birdie of his own ten minutes later and for good measure birdie the 13th to lead by two over Bradley and by three over Robert Karlsson.
Then came what appeared at the time to be the telling blow for Bradley when he tripled the 15th and Dufner was a massive five shots clear of anyone. The final few holes however were, as most had expected and were perhaps hoping, about to play their role.
Anders Hansen handled the final few holes better than most and claimed third position ahead of Karlsson, David Toms and Scott Verplank, each with their own hard luck stories.
For Denmark's Hansen it was his only top ten finish in 22 major championships
Adam Scott was the best of the Australians, the Queenslander claiming only his 7th top ten in major championship golf when he finished alone in 7th position.
"I didn't hit a fairway on the back nine -- I hit one, actually, or two. I hit the 18th, as well," said Scott. "But I just never gave myself a chance to get the ball near the hole. And I was up-and-down a lot of holes. I mean, I did the best I could. That was a good score today, because I gave myself less opportunities than every other day.
"I hung in there well. Just for me, it's just positive. I mean, my short game is that good now. It's good enough to hang in there on the last nine of a major to keep a score going. Everything is right where I want it to be. Every day I have my opportunities. You know, you need to take them all to win these things."
John Senden finished 19th and Robert Allenby improved with a final round of 68 to be in a share of 26th.
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