American Jason Knutzon battled against the effects of a fever to move into a three-way tie for the lead at the Asian Tour in Bangkok.

Knutzon shot a four-under-par 68 to join Thailand's Kiradech Aphibarnrat and Brazilian Lucas Lee at the top of the leaderboard at the season-opening event.

The two-time Asian Tour winner had been feeling ill for the past two days but recovered sufficently to be able to card five birdies and one bogey at the Suwan Golf and Country Club.

"It's pretty amazing (to shoot this score) when you have something else to think about," he said.

"Luckily it was pretty cool this morning which helped but I was kind of gassing it in the last few holes. Anytime you shoot under par, it should make you feel a bit better.

"I took seven weeks off at the end of last year, didn't touch a club and then saw a friend and worked on a few things. I kept it pretty simple. I guess being unwell kind of slowed things down. I hit it really good."

Former Australian amateur champion Rohan Blizard is in a group of eight players one shot off the pace after carding a three-under 69.

Defending champion James Kamte had started well and was four under through 10 holes but the South African posted five bogeys coming home for a 73.