The pair went back to the 18th tee at Harbour Town Golf Links and Davis found himself in trouble after sending his second shot off greenside rocks onto the beach, the ball resting amidst short reeds in a hazard area.

As American world number six Furyk stood over a five-foot par putt, Davis decided to play from where his ball lay for his third shot rather than take a penalty drop and leave himself a chip for par.

He chipped onto the green, but the shot proved irrelevant as Davis called a penalty on himself for touching a loose impediment with his club during his backswing.

Davis informed PGA Tour rules chief Slugger White, who after consulting with colleagues determined there had been a breach of Rule 13.4 and a two-shot penalty was in order, leaving Furyk with a simple putt for victory.

“To have the tournament come down that way is definitely not the way I want to win the golf tournament,” Furyk said. “It’s obviously a tough loss for him, and I respect and admire what he did.

“To be there and be in the battle and have an opportunity to win the golf tournament, and then have to call a penalty on yourself has got to be extremely disappointing. I admire him for what he did.

“It’s a testament to our game and the people that play on the Tour, and that we have so many guys that do that.”

Furyk said the manner of the victory had made him feel a little uncomfortable.

“It’s just awkward to see it happen at such a key moment in the golf tournament. Awkward for him to lose that way, and a little awkward for me to win.

“Obviously I’m very happy to win but you almost don’t know how to react. I want to react to the crowd and kind of wave and let them know, that, hey, I’m excited, but I don’t want it to take away from Brian. It was an awkward moment, an awkward way to win.”

Davis, whose second place was his fourth runner-up finish in the last four seasons, said he had not felt his club brush the weeds.

“There was a little branch, one of the weed things sticking out, a big bunch,” Davis said.

“I didn’t feel it but I was pretty sure I saw something in the corner of my eye. So I asked Slugger to come over and check it on TV. And when he did check it on TV, I did indeed brush it on the way back, and the twig moved slightly, and obviously it was a two-stroke penalty.”

White, the PGA Tour tournament director and rules official, also credited Davis for his honesty.

“That will come back to him in spades, tenfold,” White said.

“In fact, on the putting green, after it was all said and done, I don’t know if Jim said, ’are you sure?’ but he said, ’I know I did. I could not have lived with myself if I had not called it on myself’. He’s class, first class.”

The tournament had not looked as if it would turn into a two-horse race with 21 players within six shots of the lead after the third round, seven of whom, including England’s Luke Donald, were just two shots behind Furyk’s mark of 10 under par at the start of the day.

Donald, without a win since the 2006 Honda Classic, finished with a 70 as he tied for third with American Bo Van Pelt, who had closed with a 69.

Donald’s compatriot Paul Casey, the world number seven, finished his week with a 69 to leave him in a tie for 22nd at five under.