ABU DHABI, January 16, 2014 (AFP) - The world number three Swede, almost unstoppable through the last six months of 2013, struggled to make birdies and finished the day on two-over par 74.
McIlroy did not get due reward of hitting 15 greens in regulation, and even though he was bogey-free, he made only two birdies for a two-under par 70.
There was a three-way tie for the lead with Spaniard Rafael Cabrera-Bello posting a strong finish of three birdies in his last five holes and joining England's Matthew Baldwin and France's Romain Wattel at the top of the leaderboard at five-under par 67.
Almost one year to the day when he was announced as Europe's new Ryder Cup captain, Paul McGinley celebrated the occasion with a brilliant round of four-under par 68, which tied him for the fourth place along with Dutchman Joost Luiten, South Africa duo of George Coetzee and Dawie van der Walt,
Scottish pair Marc Warren and Craig Lee and Portugal's Jose-Filipe Lima.
American superstar and world number five Phil Mickelson also did not have the start to the season that he was hoping for, making 17 pars and a bogey in a round of 73.
There was worse in store for Spain's world number 10 Sergio Garcia, who needed medical attention a couple of times for the shoulder he injured in the pro-am on Wednesday as he opened with a round of 76.
Garcia called the thick rough on the golf course "dangerous", while Mickelson also revealed even he hurt his back playing from the rough on his final hole.
Three-time Abu Dhabi champion Martin Kaymer of Germany shot a two-under par 70 and was tied 19th alongside McIlroy.
Cabrera-Bello started with a bogey, but did not drop any further shot in his round.
"It is tough out there. You need to drive it good, otherwise the rough, it's very, very thick, and it's not easy to play out of. You need to be playing very good off the tee," said the Spaniard.
"I'm pretty pleased. I have not competed for the last five weeks. Even though I have been practicing and trying to recreate competition, it's not quite the same."
Baldwin, who recently finished runner-up in last month's Nelson Mandela Championship for his career best finish in European Tour, said: "I want to win. There are plenty of guys who want to win as well, but I think looking at the year ahead, top 60 is a target. But to get a win under the belt would be superb."
The 22-year-old Wattel, who also played well in the South African tournaments towards the end of the year, said after is bogey-free effort: "This golf course is a really good test. I just tried to save par on all the bad holes."
McIlroy was pleased with his round and said: "I played well and was very happy with how I hit the ball from tee to green.
"I hit it long and straight, but just did not take advantage of some of the opportunities. It definitely could have been a bit better, but it is a solid start."
Complete first-round scores in the $2.7million Abu Dhabi HSBC Golf Championship on Thursday at the par-72 Abu Dhabi Golf Club:
67 - Rafael Cabrera-Bello (ESP), Romain Wattel (FRA), Matthew Baldwin (ENG)
68 - Joost Luiten (NED), Marc Warren (SCO), Dawie van der Walt (RSA), Jose-Filipe Lima (POR), Paul McGinley (IRL), George Coetzee (RSA), Craig Lee (SCO)
69 - Jeev Milkha Singh (IND), Tyrell Hatton (ENG), Steve Webster (ENG), Wade Ormsby (AUS), Pablo Larrazabal (ESP), Marcel Siem (GER), Michael Hoey (NIR), Oliver Fisher (ENG)
70 - Martin Kaymer (GER), Rory McIlroy (NIR), Stephen Gallacher (SCO), Thomas Aiken (RSA), Ricardo Santos (POR), Damien McGrane (IRL), Otto Hennie (RSA), Edoardo Molinari (ITA), Thomas Bjorn (DEN), Peter Hanson (SWE), Luke Donald (ENG), Jin Jeong (KOR), Eduardo de la Riva (ESP), Eddie Pepperell (ENG), Thongchai Jaidee (THA), Darren Fichardt (RSA)