Tiger Woods fired a 5-under 66 in the first round of the CIMB Classic in Kuala Lumpur to trail Troy Matterson by three shots.

The weather was pretty hot and humid making it a little difficult for the 14-time major winner.

Jeff Overton, Brian Harman, and Robert Garrigus, all Americans, are in second, one shot behind Matterson. Each of them shot 64. Matteson had eight birdies in his 63 for a one-stroke lead.

Woods seemed a little frustrated when he missed two short putts for par at the 8th and 9th holes. He was seen wiping the sweat off his face and neck with a white towel in the humid weather at the golf course.

Woods adopted a rather aggressive approach knowing that it would take about 20-under to win the tournament at the 6,909-yard Mines Resort.

"It's a different type of mindset," he said. "Going out there and shooting even par on that front nine, I just felt like I got run over."

Woods also insisted he wasn't particularly troubled by the high humidity at the golf course nor was he concerned about missing two straight birdie attempts.

"What is frustrating is turning at even par and I'm eight back. Three -- or four-under par was my number on the back nine -- if I could shoot that, I'm still right in the ballgame. I happened to get one more, which was a bonus," he added.

Woods appeared quite pleased with his efforts although he missed a birdie putt from about 10 feet on the 18th hole.

"I really started hitting the ball quite well at the end of the front nine. I happened to miss two short putts ... but also the two putts I hit were good putts at 8 and 9.

"Realistically it could have been seven or eight (under). But even at the turn, and to still post five (under), it was a nice little comeback. It's going to take 20-plus this week to win the tournament, so I've got to be aggressive and we've got to go get it."

It rained on the golf course an hour after play ended and organizers have decided to move tee times ahead by at least 40 minutes on Friday for the second round.

American golfers were quite impressive and hold five of the top six spots.