McIlroy and Karlsson share lead
Rory McIlroy outshone playing partners Tiger Woods and Luke Donald with a five-under-par opening round of 67 in Abu Dhabi.
The 22-year-old US Open champion took a share of the lead with Swede Robert Karlsson, while Woods shot a bogey-free 70 and world number one Donald a 71.
The big surprise of the opening day was the 77 by German Martin Kaymer, winner the last two years and three of the last four.
He was playing with Lee Westwood (72) and Sergio Garcia, whose 71 included the first hole-in-one of his European Tour career.
McIlroy's ball-striking was not at its best, but like Karlsson he scrambled brilliantly in his first tournament since recovering from suspected Dengue fever.
Woods was playing his first event since ending more than two years without a victory last month, but did not make the most of his chances and collected birdies only at the 11th - their second of the day - and short fourth, where he almost holed-in-one.
Donald, meanwhile, followed eight opening pars with back-to-back birdies, but could not save par from the sand on the 200-yard seventh.
McIlroy had thrown down the gauntlet with a hat-trick of birdies from the 11th, holing from nine, 12 and three feet. Then came bogeys at the 14th and 17th, but he added another birdie on the long 18th despite his wild second shot hitting the hospitality tent.
A superb pitch from the rough to three feet at the 600-yard second took him to four under and then came the added bonus at the long eighth after he had twice been in the rough and just missed the green.
He and Karlsson, who also relied on his short game more than he would have liked, were a stroke ahead of McIlroy's fellow Northern Irishman Gareth Maybin, Frenchman Jean-Baptiste Gonnet and England's Richard Finch.