US Open champion Rory McIlroy and Danish veteran Thomas Bjorn sunk late birdies to set the pace at the Dubai Desert Classic yesterday, with the pair 13-under after the second round.

Behind them lurked Martin Kaymer, who claimed his first ever hole in one, and a resurgent Lee Westwood as golf's top guns excelled on another windless day on Dubai's Majlis course.

McIlroy, Westwood and Kaymer are ranked two, three and four in the world, with only No. 1 Luke Donald absent from the Dubai leaderboard.

"This was very stress-free golf - fairways most of the time, a lot of greens and giving myself a lot of looks, so I'm really pleased with how I played today," McIlroy, 22, said.

Yet the Northern Irishman may rue several missed long birdie chances as his putting often failed to match his stellar approach play.

"It could have been better, I missed a putt on the 18th for an eagle, I missed a putt on the first for a birdie that was pretty short," said McIlroy. "I hit a couple of really good putts on the back nine which could have dropped."

Germany's Kaymer, on 11-under, said he would not be satisfied with a leaderboard finish.

"The only thing that matters is the trophy - to leave the golf course on Sunday afternoon knowing that you have beaten everyone," the 2010 US PGA champion told reporters.

"That's the pure satisfaction. A few players say they want to win, but they don't want it as much as others. Rory... he really wants to win and I'm not coming here to just play four rounds of golf in the sunshine."

McIlroy started the day on six-under, this time playing the back nine first. He teed off from the 10th hole early, a wisp of cloud shrouding the desert sun as Dubai slept yesterday, the Muslim holy day.

The back nine in Dubai is kinder than the front nine, with three par-fives and a couple of short par-fours, so he was under pressure to score low early.

McIlroy sank a birdie on the opening hole, playing a chip shot from the rough to be within a few feet of the pin, but at the 11th he came up short with an 18-foot putt that would have earned a second successive birdie.