McIlroy pips Reed by one shot to win third Dubai Desert Classic crown
Reed finished with a commendable final-round score of 65 which included an eagle on the par-five 10th hole but bogeyed the 16th to post 18-under overall.
In response, McIlroy kept his cool and birdied the last two holes - including a wedge to 15 feet and a downhill putt on the 18th - to celebrate his first title on the DP World Tour since November 2019.
"It was a battle all day. Honestly, it has been a battle all week. I really feel like I haven't had my best all week but I managed my game and played really smart," McIlroy said.
"I managed my game well, lots of room for improvements... Mentally, today, it was probably one of the toughest rounds I've ever had to play because it would have been really easy to let your emotions get in the way.
"I'm going to enjoy this. This is probably sweeter than it should be or needs to be... A really good foundation for the year."
Australia's Lucas Herbert (27), who had set the clubhouse target at 16-under overall earlier in the day, finished third.