Rory McIlroy and Luke Donald are part of a three-way tie for the halfway lead in the DP World Tour Championship.
The world numbers one and two top the leaderboard alongside Scotland's Marc Warren after another day of excellent scoring on the Greg Norman-designed Earth course in Dubai.
McIlroy, whose booming drives set up numerous birdie chances, was first to post 11-under with a 67 although he felt it should have been better.
That gave him the clubhouse lead but his 36-hole tally was matched by the final pair of Donald and Warren.
Donald extended his bogey-free streak at the Earth course to a remarkable 83 holes after 14 pars and four birdies, including one to close with at 18 following a superb wedge to three feet.
Warren, who opened with a birdie for the second straight day, had a six at the seventh but played the final 11 holes in four-under to share the spoils with the top two.
Branden Grace, a four-time winner on the European Tour this year, shares fourth place on 10-under with South African compatriot Louis Oosthuizen.
Grace's 65 gave him a two-shot lead at one point while Oosthuizen's 67 included an eagle at 14.
Sergio Garcia, playing in his first event since the Ryder Cup in September after undergoing laser surgery to correct his astigmatism, carded the round of the day, a remarkable course-record 64 which included two eagles, nine birdies, two bogeys and a triple-bogey seven. That left him at seven-under.
England's Danny Willett is in a big pack at eight-under after achieving the rare feat of back-to-back eagles (at 14 and 15) in his 65.