The world's top-ranked players, Rory McIlroy and Luke Donald, were involved in a three-way tie at the top of the leaderboard at the halfway stage of the US$8 million ($9.7 million) DP World Tour Championship in Dubai.
At the Earth course of Jumeirah Golf Estates, world No1 McIlroy and No2-ranked Donald were joined at 11-under par in the season-ending European Tour event by Scotland's world No189 Marc Warren.
McIlroy (who shot a 67) missed sole possession of the lead when he failed to make a birdie on the final hole, which was played from the forward tee and reachable in two, while Donald (68) joined him and Warren (67) on top with a textbook birdie on the par-5 hole.
The leading trio were one shot ahead of South African duo of world No6 Louis Oosthuizen (67) and Branden Grace (65). Another South African, 2011 Masters champion Charl Schwartzel (67) and Scotsman Richie Ramsay (68) were tied sixth at nine-under while Australian Marcus Fraser (67) was in a group of 10 a stroke further back.
McIlroy, who complained of having a massive headache the previous night, said he felt all right on the golf course as he mixed six birdies with a solitary bogey on the fourth hole.