Canadian rookie Adam Svensson has taken the early lead at the Sony Open in Hawaii after carding a first-round nine-under 61.
American Andrew Putnam initially made himself the man to beat after making nine birdies in his opening round 62, with a bogey on the 15th the only blemish on his day.
But a run of four birdies through holes 11 to 14 from 25-year-old Svensson put him joint top before he grabbed the sole lead with a 10-foot birdie putt on the par-five 18th.
Seamus Power is tied for 112th and will need to be good on Friday to make the cut. The Waterford golfer started his back nine with a birdie, but gave two shots back on the next with a double bogey on his way to a two over 72.
Jordan Spieth, meanwhile, had a disappointing start to the year after a winless 2018 as he was forced to settle for a three-over 73, putting him at joint 127th.
Starting on the back nine, the world number 17's only birdie came on the par-three seventh hole and was immediately followed by a bogey, his fourth of the round.
Matt Kuchar carded a flawless seven-under 63 to put him two shots adrift of Svensson, while last year's winner Patton Kizzire makes up a 12-strong pack on three under.
Masters champion Patrick Reed sits tied in 29th place on two-under 68 along with Scotland's Russell Knox, while England's Ian Poulter mixed seven birdies with six bogeys to finish one under and joined in 52nd place by compatriot Luke Donald.