David Toms thrashed Ryder Cup team-mate Chris DiMarco 6&5 to win the WGC-Match Play title at La Costa on Sunday.
Toms, the 2001 USPGA champion, was in sparkling form all weekend
The biggest victory in the history of the event brought the 38-year-old American a cheque of £686,052.
England's Ian Poulter lost a superb third-place play-off to Retief Goosen when the South African chipped in from 15 feet at the second extra hole.
Goosen earned £295,530 while Poulter, who is up to a career-high 32nd in the world, picked up a cheque for £237,479.
The 29-year-old Ryder Cup star, who was beaten by Toms' brilliant play on Saturday, can consider himself unlucky to have come up against two players in such form on consecutive days.
In another dominating display, Toms needed just 31 of the scheduled 36-hole final to seal victory.
The previous largest winning margin in a final was Darren Clarke's 4&3 win over Tiger Woods in 2000.
"I've won a few tournaments along the way but I never felt that type of ease on a golf course," said Toms, who had just four bogeys over 116 holes of play.
"I don't know how to explain it. I felt at peace all week."
Runner-up to Woods in 2003, Toms was six holes up after the first 18 holes thanks to a blistering back nine.
Just as he did in Saturday's semi-final against England's Ian Poulter, Toms shifted into top gear after the turn with birdies on five of the next six holes to surge in front five-up.
Toms then watched as DiMarco folded under the pressure and carded bogeys on 16 and 17 to add two more holes to his advantage.
With the title slipping away, DiMarco gained some respite with a birdie on 18 to trim Toms's lead by one and grab a small amount of momentum to take into the afternoon.
But when the pair resumed after lunch, little had changed.
DiMarco kept pace with Toms for the first five holes but, with the pressure mounting, DiMarco faltered as Toms birdied six and seven to increase his advantage to eight-up.
And when DiMarco bogeyed the eighth it looked as though it was all over.
But the New Yorker is a gritty competitor and when Toms dropped a shot at the ninth DiMarco carded three straight birdies to reduce the gap to six with six to play.
But the DiMarco comeback came to an end on the par-four 13th when Toms drained a 10ft putt to clinch victory.
"I thought I was going to go in early but like I said yesterday, [DiMarco] would hang in there and fight it out no matter what the outcome," said Toms.
"It was probably the best week of driving the ball I ever had and that was probably key to winning."
DiMarco said: "Boy, he's solid. They have a good champion and my hat's off to him. The stretch nine through 17 got me."