Fellow American Keith Mitchell matched the day's best score, a seven-birdie 63, to jump into a tie for third with Chez Reavie (66), four shots behind Kuchar, who has made just one bogey through 54 holes.
Matt Kuchar overcame three early bogeys that cost him the lead with flawless golf and two key birdies on the back nine to close with a 4-under 66 and win the Sony Open for his second PGA Tour title this season. Needing to birdie the last four holes to qualify for the weekend, he ran off two birdies, missed a 3m birdie putt and then narrowly missed chipping in for eagle. He joins Xander Schauffle in the two-win club for this season and now has almost eight months to notch the first three-win season of his long, consistent and successful career.
"It was awfully steady, bogey free, the kind of golf I like to play, give yourself enough opportunities, enough will go in". "It is the golf I like to play to stay out of trouble", he said.
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. This time, he wouldn't let go, with three birdies over his final four holes to emphatically seal a four-shot victory.
Kuchar ended a three-year drought by winning the Mayakoba Classic in Mexico last fall. Lahiri bogeyed the 460-yard par-4 sixth, as he landed on the green in 2 and three-putting, moving him to one-over for the round.
Matt Kuchar hits from the 10th fairway during the second round of the Sony Open on Friday. He used eight birdies to complete the feat, including three on his final seven holes.
Kuchar matched the lowest 36-hole score of his PGA Tour career.
Super-consistent Marc Leishman is on track for another big US PGA Tour payday but the Sony Open title appears nearly out of reach going into the final round. However, his bunker shot got the ideal bounce off the green and one more off the flagstick for an impressive ending. "I have to stay aggressive".
Marc Leishman (64), Hudson Swafford (64) and Chez Reavie (67) also finished in a tie for third.
It was a hard day for 11-time PGA Tour champion Spieth, who had four bogeys and just one birdie to be tied for 127th and 12 shots off the pace. And he'll be back in Maui for the 2020 Tournament of Champions, suddenly a major player again and one who looks capable of vying for his first career major in the coming months. He closed with a birdie Saturday to cut Kuchar's lead to just two.