Justin Thomas is well poised after the first round of the CIMB Classic, but it is fellow American Bronson Burgoon who holds a one-shot lead in Kuala Lumpur.

Thomas, back in action for the first time since he was the top-scoring American in their Ryder Cup loss to Europe, started with a six-under 66 on the upgraded West course in a tournament he has previously won on two occasions.

The former world number one, who won his first PGA Tour title at this tournament three years ago, birdied three of the first four holes after starting on the back nine before dropping a shot at 14.

Despite making another gain at the first, Thomas was back at two under again following another bogey at the second, but took his tally of birdies to eight with four in his last five holes to take a share of sixth place.

Burgoon is the surprise name at the top of the leaderboard courtesy of a superb nine-under 63.

The Texan, ranked 162 in the world, was one over through four holes after also starting on the back nine, but three consecutive birdies and an eagle three at 18 put a spring in his step.

Burgoon went from strength to strength after the turn, picking up another five shots to take the clubhouse lead with a round that would not be bettered.

Austin Cook is just a shot off Burgoon, with Scott Piercy, Billy Horschel and C.T. Pan another stroke back in a share of third place.

Thomas is among a group of eight players on six under, including Paul Casey, Louis Oosthuizen and Kevin Chappell, while defending champion Pat Perez will start his second round on two under.

Danny Lee had the honour of being the first player to conjure up a hole in one on in the 2018-19 PGA Tour season, a nine-iron doing the trick at the par-three fourth.