Jordan Spieth carded an opening round of six-under 64 to share the early Sony Open lead with Chris Kirk and Taylor Montgomery at the Waialae Country Club in Honolulu in Hawaii.
Spieth hit three birdies in a four-hole stretch around the turn and, apart from a single bogey on the 13th, his only other disappointment was having to settle for par on his final hole - the ninth.
He goes into Friday's round tied for the lead with fellow Americans Montgomery and Kirk, while compatriot Harris English finished with a 65 to join a large group one shot behind.
The chasing pack on 65 also includes Olympic silver medallist Rory Sabbatini of Slovakia, while South Korea's SH Kim was five under with two holes to play when bad light stopped play.
Harry Hall finished on four-under 66, after a mixed back nine which saw him record four birdies and two bogeys, while his score was matched by fellow Englishman Ben Taylor.
KJ Choi made a rare PGA Tour appearance at the age of 52 and the South Korean is in the group at 66, which also includes Stewart Cink, who turns 50 in May.
Defending champion Hideki Matsuyama of Japan opened with a 68, one better than Australian Adam Scott.
Michael Castillo, the Kapalua club pro who qualified for his first PGA Tour event at the age of 60 while battling cancer, opened with a 79.
In a rare moment, Ryan Armour hit a hole-in-one on the 17th, just the sixth time an ace has been hit on the penultimate hole in the last 40 years at the Sony Open.
After his round, Spieth said: "The stuff I've been trying to work on in my stroke I decided to go full trust from the get-go today, and to see those go in was a nice confidence boost and led to a good putting day. I had a number of wedges. You know, it stinks, par number nine.
"I hit a really nice drive and it caught the lip of the bunker and hung - just like number eight, went through a bunker and I was standing on it. I kind of had a couple drives that were really close on the last two holes to being another stroke or so.
"So I feel like I left a couple out, but I also really had fun today. Like, I had fun playing the shots in the wind. It's fun when you know you hit a good one because out here the ball is just going to roll 70 yards and it's like, wow. If you miss the fairway you're way back, but when you hit it it's like, I got a nice sand wedge into this green now.
"It can be a real fun golf course once you start peeling it down these fairways."
Watch the Sony Open in Hawaii throughout the week live on Sky Sports. Live coverage continues Friday with Featured Groups from 6pm on Sky Sports Golf, ahead of full coverage from midnight.