Rory McIlroy landed a $15million payday with his second FedEx Cup victory in the space of four years, as he produced a dominant final round in the TOUR Championship.
-18 McIlroy
-14 Schauffele
-13 Thomas, Koepka
-9 Casey
Scores include pre-allocated figures; McIlroy also shot the low 72-hole score from Schauffele, with Casey third
Rory McIlroy became the first winner of the FedEx Cup following its controversial revamp as he took the TOUR Championship for the second time in four years.
On a tricky day at East Lake, McIlroy's four birdies over the first 13 holes provided a cushion from which he could drop shots at holes 14 and 15, with a brave par putt at the next all but ending the contest before a birdie at 17 did just that.
"To play like that, alongside Brooks, and to win the FedEx Cup - it's awesome," said McIlroy as he celebrated after a closing birdie for a four-shot win.
"My goal was to shoot the lowest score of the week - that was my goal going out. Such a cool way to end what for me has been a great season."
Xander Schauffele was unable to quite get on terms with McIlroy, making a bogey shortly after each of his three birdies, but stayed the course to finish second and narrowly miss out on the FedEx Cup - just as was the case in 2017.
Justin Thomas, who won it then, shared third place with Brooks Koepka, the latter stumbling during a final-round pairing with McIlroy, with Paul Casey a distant fifth in a tournament which very quickly concerned only a select few.
McIlroy produced the best 72-hole score and also did enough to overcome a five-shot starting deficit with Thomas, who began the week as the man to catch in a new and experimental format.
It was announced a year ago that from 2019, players would be allocated a starting score before teeing off at East Lake, that score depending on their FedEx Cup position entering the final event of the season.
For McIlroy, who won the PLAYERS Championship in March and added the Canadian Open in June, that meant beginning at five-under and five shots off the pace-setting Thomas, with Patrick Cantlay, Patrick Reed and Koepka separating the two.
With the first three all struggling somewhat, it was Koepka who looked to pose the biggest threat to McIlroy and he in fact started Sunday's final round with a one-shot lead over a player he got the better of in Memphis recently.
McIlroy, though, dominated the final two-ball from an early stage, and when Koepka double-bogeyed the seventh hole after another wayward drive, the Northern Irishman found himself in a commanding lead.
To his credit, Koepka birdied the eighth to get back on track but McIlroy's fortune on the same hole, where a sprinkler may have kept his ball from tumbling into the lake which gives the course its name, proved vital in shaping the outcome of the event.
From there, McIlroy was in total control throughout the middle part of the round and as Koepka bogeyed three in a row from the 12th, only Schauffele could now catch the leader.
As McIlroy made two mistakes in a short space of time, the lead was halved to two, but the four-time major champion saved par at the 16th before birdieing the 17th, a decisive double which confirmed that he would win the TOUR Championship just as he did in 2016.
Back then, McIlroy won a play-off for the $10million bonus. Two years on and with another $5million in the treasure chest, this victory was in the end far simpler and perhaps of even greater significance, as he looks to become a major contender once more in 2020.
One more birdie at the last confirmed that the margin of victory was four, the number he'll want to escape as he seeks major number five. After a performance like this, he'll wish that quest could begin sooner than April.
The third round of the Tour Championship in Atlanta was suspended on Saturday following lightning strikes at East Lake which resulted in some spectators being taken to hospital, the PGA has confirmed.
Play had been suspended from around 4:15pm local time as the weather worsened, with a lightning bolt then striking a tree near the 16th tee around half an hour later.
Bad weather had also interrupted Friday's play, which saw world number one Brooks Koepka sit at the top of the leaderboard on 13 under.
Following confirmation of Saturday's play being suspended, broadcaster Sky Sports reported at least five people had been treated and taken to a nearby hospital, where they were said to be awake and responsive.
A statement from the PGA Tour read: "At 4:17 p.m., the third round of the TOUR Championship was suspended due to inclement weather in the area. At 4:45 p.m., there were two lightning strikes at East Lake Golf Club; a tree near the range/15 green/16 tee was hit, and debris from that strike injured four people.
"EMT (emergency medical technicians) tended to those fans and two others immediately and transported them from the property via ambulance for further medical attention. Our latest report is that their injuries do not appear to be life-threatening.
"Due to these circumstances, the third round has been suspended for the day and play will resume on Sunday at 8am ET.
"The safety of our fans, players and partners is of the utmost importance. We will provide further updates as they become available."
When the players were taken off the course, American Justin Thomas was at the top of the leaderboard at 12-under-par, even on his scorecard through five holes on day three.
Nothern Ireland's Rory McIlroy was on 11 under, one over for the day after a bogey at the first, while Koepka dropped shots at both the first and third holes to also be in a tie for second place.
Xander Schauffele was 10 under, one over for the day, while Chez Reavie was at nine under after going three under through seven holes, alongside England's Paul Casey who was even par after six.
World number one Brooks Koepka sits on 13 under at the top of the leaderboard after the second round of the Tour Championship.
The American signed for a three-under 67 on day two, mixing four birdies - including a two-putt birdie on the par-5 18th - with a bogey for a one-shot lead in Atlanta.
Justin Thomas carded a round of 68 while Rory McIlroy shot back-to-back birdies on his final two holes to take a share of second place on 12 under.
The season-ending tournament uses an adapted sliding scale scoring format to decide the winner of the USD 15million (£12.3m) FedExCup first prize, meaning Thomas started the week on 10 under and Koepka began on seven under.
Koepka got off to a steady start in the second round, following up his first birdie on the par-3 sixth hole with two more in a row.
But a weather delay interrupted his momentum and it was only at the last hole that he was able to edge ahead.
McIlroy took better advantage of the 90-minute delay, firing his first birdie at the 12th before finishing his round with a 15-foot birdie putt on the 17th and a closing birdie on the 18th.
The Northern Irishman said he had "scrambled well" but admitted luck had played its part.
"I got lucky on 18," he told Sky Sports.
"I didn't hit a very good drive, and then I had a shot to get it up near the green with my second, and then once I hit that, I had a great lie for my third, and I just sort of rode my luck the whole way along that hole.
"Being three or four behind those guys for the most part of the day and then to catch JT (Justin Thomas) and only be one back of Brooks, it was nice to finish the way I did."
FedEx Cup leader Justin Thomas saw his controversial two-stroke lead wiped out on the opening day of the Tour Championship as he was caught by a couple of his main rivals.
There has been much debate about the adapted sliding scale scoring format for the season-ending tournament which saw points leader Thomas tee off at 10 under, two better than Patrick Cantlay.
But while Thomas struggled to a level-par 70, getting back to 10 under with a birdie at the last, Xander Schauffele, who started six shots back, and Brooks Koepka, who began with a three-shot deficit, were in much better form with rounds of 64 and 67 respectively.
Rory McIlroy would have joined the three-way tie at the top had he made an eight-foot birdie putt at the last, but after a heavy-handed attempt he made the returning par putt and signed for a four-under 66 to move to nine under.
Ultimately, three birdies in his final six holes, having had one bogey sandwiched by two birdies on the front nine, left the Northern Irishman satisfied.
"I got off to a decent start. It is so tough to shoot a score around here if you don't hit it in the fairway," he told Sky Sports.
"To play the back nine in three under and get in with a decent score is very nice.
"I would have liked to have birdied the last but I'm right there with three rounds to go.
"If I can replicate this round of golf three more times I think I'll have a good chance."
Koepka, the reigning US PGA champion, also fancies his chances of winning the USD 15million (£12.3m) first prize.
Bogeys either side of the turn appeared to have halted his momentum after picking up two strokes in his opening five holes but three birdies in his last four saw him catch Thomas.
"Tied for the lead is nice. There is opportunity," the American said.