Graeme McDowell birdied his final hole to take a one-shot lead after the third round at the Saudi International on Saturday.
Following a difficult front nine, McDowell made three straight birdies on the 12th, 13th and 14th before finishing with another on the par-four 18th at the King Abdullah Economic City.
The Northern Irishman, who last won on the European Tour in 2014, finished with four-under-par 66 to take him to 12-under overall, one shot clear of France's Victor Dubuisson.
"The putter has been ice cold over the last couple of days but it heated up a bit on the back nine," McDowell said. "It was really pleasing to get a few birdies there because I think the back nine has played difficult. I'm going to have to putt well to have a chance tomorrow.
"I keep an eye out for Victor, and it's nice to see him up there on the leaderboard."
Dubuisson carded a bogey-free 65, with birdies on the first three holes before adding two more on the back nine. Gavin Green dropped strokes on 14th and 15th but remained in contention for a maiden European Tour title at nine-under.
Defending champion Dustin Johnson is tied fourth on seven-under after a second consecutive round of 68, which included five birdies and three bogeys.
World No1 Brooks Koepka fired a 65 at Royal Greens Golf and Country Club for his best round since shooting the same score in the final round of the World Golf Championships-FedEx St. Jude Invitational in July.
It was a big step forward for the four-times major champion, who is playing only his second tournament since recovering from a knee injury sustained in October.
Koepka sits six shots off the lead in seventh spot alongside fellow American Phil Mickelson and Belgium's Thomas Detry.