Rory McIlroy claimed his second FedEx Cup title despite briefly stumbling late during his four-stroke win at the Tour Championship on Sunday.

McIlroy shot a four-under 66 in the final round at East Lake in Atlanta, ending up at 18 under and clear of Xander Schauffele (70) to claim the $15million prize.

The Northern Irishman also won the FedEx Cup in 2016. He and Tiger Woods are the only golfers to win two FedEx Cups.

The 30-year-old appeared en route to an easy victory in the final round, holding a four-stroke lead through 13 holes.

But he picked up his first bogey of the round on the 14th, then bogeyed the par-three 15th. Then, he hit his drive on the par-four 16th into a fairway bunker. With his lead cut to two strokes, disaster loomed, but McIlroy saved par on 16.

He then knocked down a 16-foot putt for birdie on 17 to build a three-stroke lead.

As fans surrounded the 18th green en masse, McIlroy made a nice save from a greenside bunker, then holed a short birdie putt to finish in style.

"Such a cool way to end what for me has been a great season," McIlroy told NBC.

"I'm so thankful … I couldn't be prouder to be your 2019 FedEx Cup champion."

McIlroy's brief struggles on his back nine opened the door for Schauffele and Brooks Koepka, but they could not capitalise.

Schauffele shot a final-round 70. Koepka bogeyed 12, 13 and 14, and needed a birdie on 17 to salvage a 72 and a tie for third with Justin Thomas, five shots behind McIlroy for the title.

Thomas shot a 68 on Sunday and birdied 16 and 18 to boost his payday.

Paul Casey finished fifth, nine shots behind McIlroy, despite a final-round 72.

Adam Scott, Tony Finau and Chez Reavie finished sixth through eighth respectively, and Patrick Reed, Kevin Kisner and Hideki Matsuyama tied for ninth.