Justin Thomas has moved ahead of the field by two strokes after carding a six-under-par 66 in the second round of the CIMB Classic in Kuala Lumpur.
The American is 14-under-par at the halfway stage of the tournament after scoring six birdies in an unblemished round on the course.
Anirban Lahiri is the closest challenger as he sits 12-under-par after shooting eight birdies, but he squandered the chance to edge nearer to the top spot due to a double bogey on the 18th hole.
Meanwhile, Paul Casey, who was one shot off the lead after the first round, has dropped seven strokes behind the lead after hitting just two birdies and a double bogey.
Adam Scott climbed up the leaderboard to put himself five-under-par after carding three consecutive birdies on the front nine.