Bradley Dredge and Robert Karlsson were the front runners midway through a tense final round of the Commercialbank Qatar Masters presented by Dolphin Energy.
Joint overnight leader Dredge picked up one shot over his opening nine holes in glorious sunshine at Doha Golf Club, while former European Number One Karlsson made his move with a three under par opening nine to progress to 11 under.
Australian Brett Rumford remained in contention a shot back with a hard-earned two under par front nine, with defending champion Alvaro Quiros a further shot off the pace.
Last year's winner made quiet but determined progress with a second birdie of the day at the ninth greeted by a fist pump from the Spaniard as he moved to nine under.
Lee Westwood made an electrifying start with a long birdie putt on the first green quickly followed up by a tap-in at the second after a superb approach as back-to-back birdies took The Race to Dubai champion temporarily to the top of the leaderboard.
But, with a new driver in the bag, a wayward tee shot at the par four fourth resulted in a two-putt bogey before he wiped out his early hard work with a second consecutive dropped shot.
The World Number Four reached the turn at one over for the day, alongside Oliver Wilson at eight under, after a third bogey of the day at the ninth.
Joint overnight leader Paul Casey slipped off the pace and down to seven under with a three over par front nine.