Dane Thorbjørn Olesen was leading the race for the first leg of The European Tour's Middle East swing at the Abu Dhabi HSBC Golf Championship.
With one hole to play the 22 year old, three times a runner-up in his rookie year on The European Tour last year, was eight under par and three ahead of Scotland's former Open Champion Paul Lawrie, Englishman Robert Rock and Swede Robert Karlsson.
Rory McIlroy, joint overnight leader with Karlsson, was amongst the later starters, but he was twice in sand on the opening hole.
The second of them found a plugged lie and a bogey dropped him to four under, but playing partner Tiger Woods improved to three under with a six foot birdie putt.
Earlier Lee Westwood refused to concede defeat to a neck problem.
England's World Number Two was in severe danger of missing the halfway cut after five bogeys in the first 12 holes of his second round.
But Westwood, grimacing as he swung, then produced a hat-trick of birdies and with a second successive level par 72 looked safely through to the weekend.
Not so defending champion Martin Kaymer, though. Winner of the title three times in the last four years, the World Number Four had opened with a 77 and improving four strokes on that on his return was never going to be enough to keep him alive in the event.
Westwood's trainer Steve McGregor said: "Lee has come into the tournament with some tightness and that can radiate down his arm through the nerve."
Sergio Garcia, playing with Westwood and Kaymer, was in a tie for the lead when he went to the turn in 32, but with a front nine containing eight pars and a bogey on the fifth for the second day running he had to settle for a 69 and four under aggregate.
Ireland's three-Major winner Padraig Harrington stood five under after four successive birdies at the start of the outward half, but then had a three-putt bogey on the short seventh.
Olesen had a chance to extend his advantage on the par five 18th, but instead was in a bunker for three, failed to get up and down and with a bogey six posted a 67 and seven under total.
It left him only one in front of Karlsson after his ten footer on the third.
McIlroy’s start became even worse when he double bogeyed the 439 yard third, going over the green from a fairway bunker and leaving his next shot from more sand short in the rough. From joint first he crashed to 17th, but a 20 foot putt on the next brought him back to three under.
Woods was in the same bunker off the tee and with his first bogey of the tournament returned to two under, while World Number One Luke Donald, the third member of the group, remained one further back after three opening pars.
It left him only one in front of Karlsson after his ten footer on the third.
McIlroy’s start became even worse when he double bogeyed the 439 yard third, going over the green from a fairway bunker and leaving his next shot from more sand short in the rough. From joint first he crashed to 17th, but a 20 foot putt on the next brought him back to three under.
Woods was in the same bunker off the tee and with his first bogey of the tournament returned to two under, while World Number One Luke Donald, the third member of the group, remained one further back after three opening pars.
