Lee Westwood came from three behind to one in front as overnight leaders Rory McIlroy and Thomas Bjorn struggled at the Dubai Desert Classic.
Three behind at the halfway point, Westwood shot a five-under-par 67 and will go into the final round with a one-stroke lead.
Overnight leaders McIlroy and Bjorn shot 72 and 73 respectively, Northern Ireland's US Open champion going into the water on the short seventh and Bjorn doing the same at the 564-yard last.
That led to the 40-year-old Dane's third bogey in the final four holes and he is now down in joint ninth place on 12 under, three behind Westwood.
McIlroy, who won his first professional tournament on the Emirates course three years ago, is only two back in a tie for fifth, but knows that unless he plays better Westwood is likely to grab his world number two spot back.
Joint second on 14 under are Scotland's Stephen Gallacher, German Marcel Siem and Spaniard Rafael Cabrera-Bello.
Not one of them is in the world's top 100, but they all need no reminding that England's Robert Rock managed to upstage Tiger Woods and the world's top four in Abu Dhabi only two weeks ago.
Westwood is seeking a third title in his last six starts, having left fields for dead in South Africa and Thailand at the end of last year.
"It's not like I've forgotten how to win," the 38-year-old from Worksop told Sky Sports. "I've won 30-odd times, so I'm used to knowing what to do when I'm leading.
"I played nicely again. I got off to a good start with three birdies in the first four, hit a lot of quality iron shots and rolled the ball well on the green."
A fourth birdie of the day on the seventh was sandwiched between two bogeys, but when he picked up further shots on the 10th, 12th and 13th he moved into a tie for the lead and parring in from there was good enough to leave him out in front on his own.
That was because of Bjorn's poor finish and a real mixed bag from McIlroy.
McIlroy also had three back nine birdies, including on the 18th when he found the green in two for the third day running, but he had taken six on the long 10th, failed to get up and down from a bunker on the 14th and could not recover from a bad drive two holes later.
The 22-year-old did well not to drop another at the 359-yard 17th. He went boldly with driver off the tee, pulled it into a small bush and after hacking out rescued his four with a superb chip.
"It was pretty ragged to say the least," he said. "Conditions were a little tougher - the wind was up and that put me off a little bit.
"The greens got firmer and the pin positions were a little tougher. I'll go to the range and try to iron it out.
"I just had to try to hang in there and stay as close to the lead as I could. To be only two back is a bonus - I feel it could have been worse.
"Two shots over 18 holes is nothing. I still feel in a pretty positive frame of mind and the windier it is tomorrow the better. It will make it a tough battle."
Gallacher had a hole-in-one at the 15th in his opening 69 - it won him a car - and is seeking only his second European Tour victory. The first came at St Andrews in the Dunhill Links championship eight years ago.
"I drove it well and have been hitting my irons pretty solid," said the 37-year-old.
Cabrera-Bello and Siem also have only one Tour title to their name. The Canary Islander's came with a closing 60 in Austria three years ago, while Siem's sole success was also in 2004.
Alongside McIlroy are world number four Martin Kaymer, Gallacher's compatriot Scott Jamieson and Swede Joel Sjoholm, whose second successive 66 was the low round of the day.
