FINAL LEADERBOARD US unless stated -15 T Purdy -14 S O'Hair -11 V Singh (Fij), B Tway, D Barron

The 31-year-old American finished on 15 under, denying overnight leader and compatriot Sean O'Hair by a single stroke in Irving, Texas.

"It feels great," Purdy said. "This has been my dream my whole life."

Vijay Singh missed out on regaining the world number one spot from Tiger Woods after finishing joint third with Americans Bob Tway and Doug Barron.

The Fijian needed a solo third-place effort or better to reclaim the top spot from the American, who missed the cut on Friday.

I played my heart out but Ted is long overdue Overnight leader and runner-up Sean O'Hair

Singh's Sunday charge included a hole-in-one at the 17th, his first ace since the 1996 USPGA, and a birdie at the last.

Despite just failing to return to number one, Singh remained philosophical.

"It doesn't matter, whatever happens happens," he said.

"I'm not concerned about that anymore. I was trying to win the golf tournament."

But it was to be Purdy's day as he completed a flawless final round to card a 15-under total of 265.

"I've been persistent, I've been all over the world playing and now I'm happy as hell," said the American, who has twice finished as a runner-up on the tour.

Purdy had started the day two shot behind leader O'Hair, who did not see things go his way in Texas.

The 22-year-old cancelled out his two birdies on the front nine with two bogeys before the turn.

I've been all over the world playing - this is the pinnacle Ted Purdy

And then he followed a birdie at the 13th with a bogey at the next and saw his eagle attempt at the 18th land 15 foot short of the hole.

"I played my heart out but Ted is long overdue," said O'Hair. "I learned a lot about what it takes to win out there."

World number three Ernie Els birdied four of his last five holes for a final day four-under 66 to tie for 10th.

While Phil Mickelson was a shot further back on 272 after a closing round of 67.