Washington (AFP) - Rory McIlroy rolled in a 14-foot birdie putt at the fourth hole of a sudden death playoff to edge Ryan Moore for the USPGA Tour Championship and claim the $10 million (S$13.5 million) FedExCup play-off bonus.

With the playoff prize and the $1.53 million winner's cheque, four-time major champion McIlroy earned a total payday of $11.53 million at East Lake in Atlanta, Georgia.

World no. 2 Dustin Johnson finished tied for sixth but after coming into the season finale atop the FedExCup standings would have still claimed the play-off bonus if either Moore or Kevin Chappell had won the tournament.

Chappell was eliminated at the first hole of the play-off - the par-five 18th where McIlroy missed a six-foot eagle attempt that would have won it all.

Moore drained a nine-foot birdie putt at the first play-off hole and he and McIlroy returned to play 18 again, both emerging with pars, as they did at the third play-off hole, the par-three 15th.

The fourth play-off hole took them to the par-four 16th, where McIlroy belted a 328-yard drive. Moore had made his par-saving putt when McIlroy stepped up and drained his 14-foot birdie attempt.

McIlroy's triumph came at the same 16th hole where he surged into the play-off mix by holing out from 140 yards out in the fairway for eagle.

He followed that with a tap-in birdie at 18 to cap a 64 to join Moore, who also carded a 64, and Chappell, who shot a 66, on 12-under par 268.

England's Paul Casey also posted a 64 to finish alone on 271. Japan's Hideki Matsuyama signed for a 69 for 274.

Johnson, whose three victories this season include his first major title at the US Open, the WGC Bridgestone and the BMW Championship two weeks ago, started the day tied for the lead with Chappell but carded a three-over 73 to finished tied with Justin Thomas on 275.