McIlroy carded a two-under-par final round 70 at the Emirates GC for a tournament record equaling tally of 22-under, leaving him three shots clear of Alexander Noren of Sweden.
The Northern Irishman's multi-million dollar lawsuit against his former management company
-- who are also counter suing him -- is scheduled to begin in a Dublin court Tuesday, but throughout the week McIlroy has shown no signs of being distracted by it.
In fact as the protracted legal proceedings have rumbled on without an out of court settlement, McIlroy's form has picked up.
His last seven appearances in European Tour events have seen him secure four wins -- including to major titles -- and three runners-up spots.
He also starred in Europe's defense of the Ryder Cup at Gleneagles.
McIlroy narrowly missed out on winning his 2015 opener in Abu Dhabi, but after a first round 64 in Dubai was never headed, reclaiming a title he last won in 2009 -- then his maiden success.
"It's nice to be able to put my name on that trophy again," McIlroy told the official European Tour website.
"It felt like I was coming second every time I was teeing it up so it was time for a change and obviously the only way I wanted to go was one better and thankfully I was able to do that today."
McIlroy started the final round four shots clear and was never seriously challenged despite Noren's superb final round of 65.
A solitary bogey at the seventh was mixed with three birdies and he could afford to par home down the stretch with his lead intact.
"I played very nicely all week; I did what I needed to do today. I didn't play quite as well as the first three days but I played a solid round of golf and kept my nose in front," he added.
Former world number one Lee Westwood looked set to make a move with three birdies in his first five holes, but a double bogey on the ninth ended his charge and he fell away further on the back nine.
Defending champion Stephen Gallacher of Scotland carded a closing 69 to finish third on 16 under, with Morten Orum Madsen, U.S. Open champion Kaymer, Abu Dhabi winner Gary Stal, South African Open winner Andy Sullivan and Austria's Bernd Wiesberger tied for fourth.