Séamus Power sits just two shots behind defending champion Kevin Na after carding a bogey-free round of 63 to finish his day seven-under-par.
Starting on the 10th, Power parred the first four holes before a hot streak of five birdies in six holes, on 14, 15, 16, 18 and the 1st. He registered two more birdies on the 5th and 6th, finishing his opening round without a blemish on his card.
Na just failed in his bid to break 60, but he still ended the day with a one-shot lead after his 61, one stroke ahead of Jim Furyk and Russell Henley.
Furyk's round included a hole-in-one on the par-3 17th.
Kevin Chappell, Patton Kizzire, Michael Thompson and China's Haotong Li are tied for fourth with Power.
Na was at eight under par through 12 holes, but he then parred five holes in a row before closing with a birdie.
"I played unbelievably well," he said. "I did everything well today and my iron play was amazing. My distance control has been great.
"I had a chance for a 59. I gave it all I could. I'm a little disappointed my putts didn't fall, some of the good putts that I hit didn't fall. But it's still a good round."
Na, who hopes to become the first player to win the Sony Open in back-to-back years since Jimmy Walker in 2014-15, made four birdies in a five-hole stretch on the front nine, then added a six-foot eagle putt on the ninth.
After logging birdies on two of the first three holes on the back nine, Na began his par streak.
Furyk, 51, went on a spectacular run late in his round. He made birdies at the 14th, 15th and 16th, then logged an ace on the par-3 17th hole, with his shot finding the cup from 187 yards out.
Furyk, who now plays primarily on the Champions Tour, hadn't recorded a hole-in-one since the 2011 World Golf Championships-Bridgestone Invitational.
"Just because I'm getting close to 52, I didn't come over here to pack it in and have a vacation," he said. "I want to play well."