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Rose almost spiked the guns of the Northern Irishman, who shared the overnight lead with Luke Donald, when he carved two shots off the previous Earth course record with a breathtaking 10-under final round of 62 containing eight birdies and an eagle.
The Englishman set his target early but U.S. PGA winner McIlroy finished with the flourish of a true champion, birdying the last five holes to clinch victory by two strokes with a closing 66 and a 23-under tally of 265.
"I just wanted to finish the season the way I think it deserved to be finished," McIlroy told reporters after winning for the fifth time in 2012.
"I didn't want the year to just tail off, I wanted to end it in real style. On the back nine I knew I needed to pull out something special and I somehow summoned up the energy from somewhere to finish with five birdies in the last five holes."
Donald (71) was tied third on 270 with South African Charl Schwartzel (68) in the final event of the European Tour season.
The 23-year-old McIlroy, who started the final round with a bogey five at the first, collected $1.33 million for landing the trophy and an additional $1 million from the tour's bonus prize pool.
"It means a lot to me to win here in this fashion," said the 2011 U.S. Open winner who was cheered on by girlfriend Caroline Wozniacki, the former world number one tennis player.
"I guess in a way Justin gave me the opportunity to win it in the way that I did.
"Seeing a target there and shooting at it definitely makes you get more focused. This is a great tournament and this is a great way to end the European Tour season," added McIlroy.
"I'm over the moon. There are so many strong players on the tour and there will continue to be a lot of strong players coming through on this tour," added McIlroy who complained of feeling unwell in the middle of the event.
The billboards in the city called the tournament 'The Greatest Show On Earth' and McIlroy and Rose did their best to live up to the billing with a red-hot exhibition of low-scoring on another sun-kissed day in the Emirate.
Dutchman Joost Luiten (276) and Scotland's Stephen Gallacher (276) also recorded hole-in-ones while Spain's Sergio Garcia shot his second 64 of the week to finish tied for ninth on 274 in his first outing since the Ryder Cup in September.
The highly-anticipated duel between McIlroy and Donald never materialised as the world number two failed to keep up the inspired form that had seen him go 102 holes in the tournament, this year and last, without a bogey.
The Englishman's remarkable scoring sequence ended when he dropped a stroke at the third and he was never able to mount a sustained final-round challenge.
Rose said he had been feeling a sense of frustration with his putter but he put that right on Sunday, especially at the last where he left a brilliant 70-foot eagle attempt hanging tantalisingly on the lip.
The big crowd circled around the 18th green were perched on the edges of their seats as the ball almost slowed to a halt at the top of a ridge before it picked up pace again and nearly went in.
"It was hero or zero there," said Rose. "I was one roll away from looking like an idiot.
"I was just trying to putt to a point on the hill and let gravity take its course. I actually got goosebumps because for a second I thought it was going to go in."
Rose's eagle effort evoked memories of the 35-footer he sunk at the 17th on the way to his Ryder Cup singles win over Phil Mickelson on the last day in Illinois.