Americans Derek Fathauer, Keegan Bradley and Justin Thomas have a share of the lead after first-round eight-under-par 64s at the CIMB Classic in Kuala Lumpur.
Fathauer had an unblemished round as he hit eight birdies, while Bradley's eagle on the 10th hole kept him in contention, despite two bogeys on the back nine.
Thomas would have edged ahead of the pack had he not dropped a shot on the sixth hole, but it is still a positive round from the 23-year-old.
Paul Casey sits just off the shoulder of the trio as he carded seven-under-par 65 with eight birdies - three of which came consecutively from the 16th hole - and a solitary bogey.
Sergio Garcia is three shots off the pace following a first-round 67, while Patrick Reed's 68 places him four strokes off top spot.