Brooks Koepka has pocketed a stunning US$4.75 million (AU$6.87 million) payday for his victory at the World Golf Championships Invitational in Tennessee.
The World No.1 is now in prime position for another huge bonus next month having cemented his position atop the PGA Tour's season-long FedEx Cup standings, courtesy of his three-shot win at TPC Southwind in Memphis.
If the big-hitting Koepka can hold on to his FedEx Cup lead through the season-ending Tour Championship in August, he will net a US$15 million bonus prize.
"It's incredible but the year is not done; there are a few more things to finish off and hopefully they can go my way," a determined Koepka said after beating a WGC field featuring 45 of the world's top 50.
Ousting overnight leader Rory McIlroy, Koepka fired a five-under-par 65 to finish at 16 under.
Former US Open champion Webb Simpson (64) was runner up at 13 under, while Victorian Marc Leishman (67) was a stroke further behind in third.
Koepka earned a maiden WGC title and second US PGA Tour victory this year, having won the US PGA Championship in May – his fourth major.
In addition to the US$1.75 million winner's prize for the WGC, Koepka locked up a US$2 million bonus for taking an unassailable lead in the PGA Tour's regular season points race.
RIGHT: Overnight leader Rory McIlroy shot 71 in the final round to drop to T4th. PHOTO: Sam Greenwood/Getty Images.
He also pocketed US$1 million by winning the Tour's Aon Risk Reward Challenge – a season-long competition based on a player's average score across a designated hole at each tournament.
"It's nice; I'm sure I can find a way to spend it," Koepka joked in his winning press conference.
"It's incredible what I have done this year. The overall consistency, I have taken my game to a new level."
Koepka adds a maiden WGC title to a trophy cabinet featuring two US Opens and two US PGA Championships, all of which he has won during the past three years.
"Any time you can win a world golf championship is special," the 29-year-old Koepka said.
"The goals are to win as many times as you can in a year, turn up for the big events and make sure you're in contention."
While Koepka cemented his place atop golf's world rankings, four-time major winner McIlroy was left to rue a Sunday collapse.
The Northern Irishman, playing in the final group with Koepka, was the only golfer in the top 10 on the leaderboard to not break par – shooting a 71 to drop to 11 under and a share of fourth.
After Leishman, Cameron Smith was next best of the Australians at six under, having posted a 68 to earn a creditable tie for 12th place.
Adam Scott signed off in style with a 67 to save a one-under total, which countryman Jason Day also signed for courtesy of a closing 70.
- Evin Priest, Australian Associated Press