Ross Fisher grabbed the initiative in the opening stages of the Abu Dhabi HSBC Championship presented by EGA final round to open up a two shot lead.
The Englishman, chasing a first European Tour title since landing the Tshwane Open in 2014, began the day level with Thomas Pieters on 16 under par.
A spectacular eagle from 50 feet on the second gave Fisher the outright lead, and although Pieters birdied the same hole, a tee shot to three feet on the short fourth saw Fisher pick up another shot.
At 20 under par he led by two from EurAsia Cup team-mate Pieters and four-time Major winner Rory McIlroy, who had picked up shot at the second and fourth.
Defending champion Tommy Fleetwood and his fellow Englishman Matt Fitzpatrick were then tied for fourth on 16 under.
Pieters slipped back with consecutive bogeys on the fifth and sixth, although he did get one of those dropped shots back on the eighth to remain in touch on 17 under.
Fleetwood, Fitzpatrick and France's Alex Levy were then in need of quick birdies on 16 under if they were to mount a late title tilt.
Race to Dubai champion Fleetwood began for home with a birdie from 12 feet on the tenth, and when Fisher drove into dessert scrub on the same hole and eventually did well to salvage a bogey the top three were sepaqrated by just two shots as Pieters complketed a routine birdie to join McIlroy on 18n under.
Fleetwood holed a 15 footer on the 12th to make it a three-way tie for second, but Pieters' challenge hit the rails on the 11th as he tangled with a bunker and ran up a double bogey.
The Fleetwood charge continued with a gain from eight feet on the 13th, and he then drew level with Fisher by rolling in a 30 footer on the 15th.