Rory McIlroy and Thomas Bjorn head into the weekend with a share of the lead at the Dubai Desert Classic.
McIlroy, three shots behind after the first round, sunk seven birdies on Friday, including a chip-in on No. 8, to overtake first round leader Rafael Cabrera-Bello with a 13-under total of 131.
Bjorn, who beat Tiger Woods here in 2001 for the title, ran off five birdies on the back nine for a 7-under 65 to tie with McIlroy.
Cabrera-Bello (69) is a shot back of McIlroy and Bjorn at 12-under.
Fourth-ranked Martin Kaymer (67) made a hole-in-one on 16 to draw within two shots of the leaders while third-ranked Lee Westwood (65) birdied his last three holes to reach 10-under.