Jon Rahm made history as he saw off a world-class chasing pack to become the first player to win five Rolex Series titles with a record third victory at the DP World Tour Championship.
The Spaniard went into the final round with a narrow one-stroke lead but reeled off three opening birdies to stretch that advantage before bouncing back from a bogey on the fourth with three more gains to sign for a closing 67 and finish the tournament on 20 under par.
Rahm's victory continues his love affair with Jumeirah Golf Estates' Earth Course, where he now has three wins and another top-five finish in four visits.
He also adds a fifth Rolex Series title to his collection, becoming the first person to achieve the feat.
McIlroy won the other prize on offer on Sunday, topping the DP World Tour Rankings in Partnership with Rolex to win the Harry Vardon Trophy for the fourth time.
The Northern Irishman capped a hugely-successful year by becoming the European Number One, World Number One and FedExCup Champion at the same time for the first time in his career.
Rahm never relinquished the lead on day four but did not look totally comfortable on the back nine, as a series of missed fairways gave hope to his challengers, who were queuing up behind him.
He took a two-shot lead to the last but there was a late twist as an errant tee-shot landed him in tree trouble and he only just cleared the penalty area with his second shot.
But his gamble paid off as he two-putted for par on the 18th green to storm to victory.
Tyrrell Hatton and Alex Noren finished in a tie for second on 18 under, with McIlroy two shots further back in fourth.
Englishmen Tommy Fleetwood and Matt Fitzpatrick were in a share of fifth place on 13 under.
Having birdied the first from 13 feet, Rahm somehow managed to hit his approach at the second through a bunker to give himself an eagle chance but had to settle for a birdie instead.
He made it three in a row from ten feet at the third before surrendering a bogey on the par-three fourth.
The Spanish star picked up a shot at the seventh courtesy of an 18-foot birdie putt and pulled off some excellent par saves before making his next birdie from 30 feet on the short 13th.
Rahm missed the fairway on the 14th but he got up and down for a superb par save there before a birdie at the 15th moved him three shots clear.
With his lead having been cut to two in the closing stages, Rahm looked in complete control until a disappointing tee-shot at the last left him with work to do.
But a brave recovery from among the trees allowed him to breathe easily and close out a straightforward win.
Rahm was thrilled with his victory. He said: "Because of Covid I never got the chance to defend my 2019 title.
"Even though I decided not to come last year I came here with the mentality of 'Well, nobody beat me in the last two years so they're going to have to beat me again'.
"I came in with that confidence. A lot of similarities to the past - the last time I won here I started at 15 under, had a heck of a front nine and I shot 20 under as well to win it.
"I like this course and this course likes me! I hope this is the third of many more.
"Hopefully people can stop telling me that it was a bad year. Three wins worldwide, three wins in three different continents.
"Yeah, it wasn't a Major Championship but it's still a really, really good season.
"We had a second boy this year, a lot of changes at home - it also helps. I got a lot of videos from my kids back home laughing and doing things.
"I do draw from some memories. Kelley (Rahm's partner) sent me a video of our youngest when he was clapping, and that's what I was thinking on the last few holes, hopefully try to make him clap a little bit more."