Victor Perez shot a second straight 65 to take the lead after two rounds at the Saudi International, with Brooks Koepka and Dustin Johnson falling further off the pace.
Frenchman Perez birdied four of his first nine holes after teeing off at the 10th but cancelled out two further gains with bogeys at the third and sixth.
However, he birdied the last to move to 10 under for the tournament and holds a one-shot lead over Malaysian Gavin Green, who had shared the overnight lead with Graeme McDowell – the Northern Irishman slipping at eight under in third.
"I was very pleased with the second round," said Perez, who led by four strokes at one point. "I think it was important to keep the hammer down after an unexpected 65 in the wind [on Thursday].
"I feel like I've been able to hole some good putts … and it also frees you up, you don't feel like you have to hit the ball really stiff. You feel like you're taking advantage of your opportunities and that's what I've done so far."
Johnson sits at five under in a four-way tie for eighth that includes Henrik Stenson, with three birdies on the back nine helping the American recover after he reached the turn one over par for his round.
Five-time major winner Phil Mickelson added a 70 to his opening 66 to remain four under for the tournament.
World number one Koepka is one under after signing for a 69 that included bogeys at the eighth and 18th.
Patrick Reed, the 2018 Masters champion, missed the cut after an even-par 70 left him at three over.