Before he even teed it up this week, McIlroy had already wrapped up the European Tour money title and the season-long points race, the Race to Dubai. But he didn't just go through the motions in his final event of the year.
McIlroy opened with rounds of 66-67-66 before finishing with another round of six-under 66.
Rose shot 10-under 62 on Sunday to finish 21 under, and McIlroy made birdies on his last five holes to beat him. McIlroy also battled Luke Donald, No. 2 in the world, for the lead over first three days.
Coming off a win last week at the Dunlop Phoenix Open on the Japanese Tour, Donald was also in good form. Dating back to last year, Donald was bogey-free for 100 consecutive holes on the Jumeirah Golf Estates, the host course in Dubai.
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It was McIlroy's fifth win of the year, and since winning his second major title at the PGA Championship in August, McIlroy has added three wins and three other top-10 finishes in eight events.
McIlroy was coming off a missed cut at last week's Hong Kong Open, and he admitted he was feeling lethargic after a whirlwind season of traveling the globe and taking a firm hold on the No. 1 ranking. In the last month alone, McIlroy has played events in China, Singapore, Hong Kong and Dubai.
But as is typical with the 23-year-old phenom, he shrugged off the bad week and showed once again why he's the best player in the game.
McIlroy heads into the brief off-season with the No. 1 ranking firmly in hand. He's expected to make his 2013 season debut at the same event where he began this year, the Abu Dhabi HSBC Golf Championship, which begins Jan. 17.
RELATED PHOTOS: McIlroy's Career in Pictures (Photo: Andrew Redington/Getty Images)