ATLANTA -- The crowd rushing to circle the 18th green. The steady chants. It all sounded so familiar to Rory McIlroy at East Lake, with one big difference.

On Sunday, it was all for him.

One year after he was an overlooked bystander as Tiger Woods celebrated the missing piece of his comeback by winning the Tour Championship, McIlroy surged past Brooks Koepka and delivered a clutch par putt when he needed it to win the FedEx Cup and the $15 million prize, the biggest payout in golf history.

"It's amazing how different things can be in a year," McIlroy said.

With two final birdies, McIlroy closed with a 4-under 66 to end a marathon day at the storm-delayed Tour Championship and finished four shots ahead of Xander Schauffele. He joined Woods as the only players to win the FedEx Cup twice since it began in 2007.

He smiled at hearing the chants "Rory! Rory! Rory!" from a gallery that came under the ropes on the 18th hole to watch the finish.

"I must say, I didn't enjoy that walk last year like everyone else did," McIlroy said. "I never took the fight to Tiger."

McIlroy had more than the $15 million prize on his mind.

He wanted to win this outright and was keeping score to the very end. The format was changed this year to give top players a head start based on par depending on their standing in the FedEx Cup. Justin Thomas was the No. 1 seed and started at 10 under par before a shot was hit. McIlroy was the No. 5 seed and started at 5 under.

He finished at 18 under in the FedEx Cup finale. His actual score was 13-under 267, better than anyone else in the 30-man field.

It will boost him to No. 2 in the world behind Koepka.

There also was a small matter of payback. McIlroy had a one-shot lead over Koepka in a World Golf Championships event last month in Tennessee but made only one birdie in the final round as Koepka blew past him to win.

They were in the final group Sunday at East Lake, and McIlroy got the best of the No. 1 player.

McIlroy thanked fans on Twitter after his victory.

Thank you to all the fans from around the world for your incredible support throughout the season especially those in Atlanta this week. It truly means so much to me. Now it's time to celebrate! ?? ? ? https://t.co/TChzWyr6uX

— Rory McIlroy (@McIlroyRory) August 26, 2019

The final round turned on the seventh hole with a three-shot swing -- McIlroy made a 25-foot birdie, while Koepka lost his tee shot in the trees and made double-bogey. There were consecutive two-shot swings on the back nine, and then it was a matter of holding off Schauffele.

McIlroy was four shots ahead until back-to-back bogeys, and he was on the verge of watching his lead shrink to one when he holed an 8-foot par putt on the 16th. Schauffele had to settle for pars, and McIlroy finished with a flourish.

He was the only player to break par all four days.

Schauffele closed with a 70 to finish alone in second, which paid out $5 million.

Thomas lost his way Sunday morning in the conclusion of the third round when he took triple-bogey on the 16th hole to fall four behind. He finished with two birdies and a 68 and tied for third with Koepka, who ended another big year with a pedestrian finish of 72.

They each earned $3.5 million.

Paul Casey shot 72 to finish fifth and earned $2.5 million.

What looked to be a shootout turned into a runaway for McIlroy.

The marathon final day -- 31 holes for McIlroy and contenders -- began with big promise for a wild chase for the $15 million prize. Four players took turns atop the leaderboard in the first 35 minutes of golf Sunday morning, which included Schauffele's first hole-in-one of his career with a 5-iron on the 240-yard ninth hole.

The third round had been suspended Saturday after lightning struck a tree and injured six spectators huddled nearby. Police said they were treated and released from medical attention later that night.

Koepka birdied the 18th for a one-shot lead over McIlroy and Schauffele. It was tight for the first hour of the final round, and then it turned quickly.

Koepka was still up by one shot when he yanked his tee shot into the trees left of No. 7 and never found it. He made double-bogey, and it became a three-shot swing when McIlroy made a 25-foot birdie putt.

McIlroy still had a one-shot lead when he stuffed a wedge to 3 feet for birdie on the 12th, and it became another two-shot swing when Koepka missed a 4-foot par putt. The next hole brought another two-shot swing -- Koepka three-putted from 18 feet, McIlroy made birdie from 12 feet.

Koepka ended the PGA Tour season with three victories, another major at the PGA Championship, a World Golf Championship and the undisputed No. 1 world ranking. He is the favorite to win PGA Tour Player of the Year again, though McIlroy at least gave players something to contemplate when they vote over the next few weeks.

The FedEx Cup counts as an official win, giving him three for the year. And he had 14 finishes in the top 10 out of 19 starts, the highest percentage of his career. Whether it's enough was of little consequence. McIlroy had the FedEx Cup and the biggest payout in golf.

"I'm going to enjoy this one tonight," he said.