Pre-tournament favourite Adam Scott is well poised but Swede Alex Noren rolled in 11 birdies to claim the first-round lead at the PGA Tour's weather-affected Butterfield Bermuda Championship.
Noren posted a career-low, 10-under-par 61 at Port Royal Golf Course to grab a two-stroke cushion with most players in the clubhouse before Thursday's play was suspended under darkness.
After starting on the back nine, Noren made seven birdies over an eight-hole stretch and chalked up his only bogey at the fifth.
He finished with three more birdies over the last four holes, including a tap-in at the last to tie the course record.
Americans D.J. Trahan, Vince Whaley, Robert Garrigus and Dylan Wu carded rounds of eight-under 63 to share second, with eight players in a tie for sixth a further shot behind.
Scott, the second-highest ranked player in the field, heads up the Australian challenge in a tie for 14th at six under.
The former world No.1 finished with a flurry, nabbing an eagle at the par-5 17th and collecting his seventh birdie of the day at the last.
"It was lots of good stuff. Seven birdies and an eagle, so that's all good," Scott said.
"I just got a little unstuck on these long par-3s. I didn't hit any of those greens. If you're missing greens, it can be tough around here, the lies can be tough.
"But I'm playing good, so I'm happy with that."
Scott won the Grand Slam of Golf in 2013 at the same Port Royal course in Bermuda and says it's great to find some form ahead of the looming Australian summer of golf.
"It was a good time to get the systems going again and come and play here at a course that I had a little bit of success on a long time ago," he said.
Fellow Australian Lucas Herbert, who captured his still only PGA Tour win to date in Bermuda two years ago, is a shot back at five under.
But Harrison Endycott (71), Cameron Percy (72) and Greg Chalmers (77) are in a major battle to make the halfway cut.
The tournament is the penultimate event of the new FedEx Cup Fall series, where tour players are vying to finish in the top 125 of the points standings to retain full status for the 2024 PGA Tour season.
Endycott is walking a tightrope, having started the tournament in 133rd spot in the FedExCup standings and falling to a projected 139th after the opening round.
Percy and Chalmers, who both turn 50 next year and will be eligible to try to join the Champions Tour, are both well out of contention to retain their cards after only having partial status this season.
American Adam Long, meanwhile, broke the PGA Tour record for consecutive fairways hit, extending it to 69 in a row before he finally missed off the tee.
He entered the tournament with his streak at 58 and easily cleared the previous record of 59.