Thomas had four bogeys, three of which were sandwiched in between one more birdie and an eagle to close out the round.
It took a while for Matt Kuchar to disentangle himself from a suddenly-crowded Sony Open leaderboard on Sunday, but when he finally put the hammer down, he did so emphatically and cruised to his second victory of the still-very-young 2018-19 PGA Tour season.
Kuchar became the first multiple victor on the PGA Tour this season, having ended a drought of more than four years when he captured the Mayakoba Classic in Mexico last November.
"I'm feeling a little let down right now", Putnam said after closing with a 68. His best season to date probably came in 2013 when he won the Memorial and the WGC-Match Play Championship en route to $5.6 million in earnings. I anticipate shooting another good score tomorrow. Just needed to make some better swings. "I just couldn't keep up with him".
Putnam, who won for the first time a year ago in the Barracuda Championship held opposite a World Golf Championship, did his best to stay in reach.
Matt Kuchar hits from the 10th fairway during the second round of the Sony Open on Friday. Now, he has the meat of the season in front of him.
Kuchar was at 14-under 126, matching the lowest 36-hole score of his PGA Tour career.More news: Kelly to Expose 'Surviving R. Kelly' Accusers on New Website
American Kuchar - who is chasing his first win since November - remains in control following his four-under-par 66 at Wai'alae Country Club in Honolulu. "I look forward to the rest of the year to try and continue to see how great this year can be".
Even so, the performance was big for Conner, who narrowly missed a full PGA Tour card a year ago.
He tied third with Americans Hudson Swafford (64) and Chez Reavie (67) and Canadian Corey Conners (64).
Spieth, who was making his 2019 debut, shot a 66 and Johnson had a 68 as they finished with a one-under 139 total. It was nice to have that pressure and be able to come through and make some birdies coming. His 64-65 weekend gave him a tie for seventh, and he now heads off to Singapore with hopes of earning a spot in the British Open.
Australian world No.18 Leishman started the final day seven shots behind leader Kuchar but posted a flawless six-under 64 on the Waialae Country Club course to be a shot further back.
"Certainly a year ago was disappointing, but to win two out of three events is insane to comprehend", Kuchar said.
Andrew Putnam took the lead over Kuchar as the two began their third round as the one-time PGA Tour victor impressed.