Rory McIlroy stole a march on nearest Race to Dubai rival Danny Willett, as Andy Sullivan took the outright lead at the halfway stage of the DP World Tour Championships.
World number three McIlroy was neck-and-neck with Willett after round one following a chip in from the bunker at the 18th on Thursday.
And the Northern Irishman carded a second consecutive four-under 68 on Friday to leave him tied fourth and four shots off the pace, but two clear of Englishman Willett.
McIlroy was one under at the turn after a bogey at six dented gains at the second and fifth holes. A strong back nine saw him make birdies at the 10th, 13th and 15th holes to leave him well in contention in Dubai.
Willett had matched McIlroy well for most of the round and was three under by the 15th, but a bogey at the par-four 16th halted his progress.
Sullivan, one of four players tied for the lead at the start of the day, enjoyed a blemish-free round of 66.
The Englishman - a three-time winner on the European Tour - birdied the last hole of the day to take a one-shot lead from Emiliano Grillo.
Grillo had a day to remember as he signed for a 64, the lowest score of the weekend so far. The Argentine went bogey free and was particularly strong on the back nine as five birdies saw him come home in just 31 strokes.
American Patrick Reed sits alone in third having birdied five of the last six holes to card a seven-under 65, leaving him three shots off the pace.
Charl Schwartzel matched Reed's score and is a further shot back, while Martin Kaymer - who was joint leader ahead of round two - is one of six players in tied seventh with Matt Fitzpatrick and Race to Dubai outsider Justin Rose among that cluster.
Ian Poulter dropped from a share of the lead to tied 23rd after a poor two-over 74, while Marcus Fraser - who was also among the first-round leaders - could only sign for a level-par 72.