The 27-year-old bagged his fourth career PGA Tour victory after closing with a round of six-under-par 64 for a total of 18-under 262 at Waialae Country Club in Honolulu.
Kim finished one shot clear of Hayden Buckley of the United States, who was looking for his first PGA Tour win.
The South Korean proved clutch down the stretch, birdying his final two holes to storm to the win after keeping himself within touching distance throughout the day.
The victory was arguably sealed with his superb chip-in from 30 feet at the 17th after his approach bounced off the green and into the rough.
"Nothing to lose," Kim said, knowing he had no choice but to go for broke.
That cancelled out Buckley's birdie at 16 which had given him the outright lead, and allowed Kim to seal the victory at the par-5 18th after two-putting for an easy birdie.
For Buckley, it was a case of close but no cigar.
"Winning on the PGA Tour is the hardest thing to do, and sometimes you just get beat," Buckley said. "And I feel like that's what happened today."
Kim is the second South Korean to win this season, joining Kim Joo-hyung who won the Shriners Children's Open in October.
Third place went to Chris Kirk on 15-under 265, while England's Ben Taylor (69) shared fourth a further shot back alongside Americans Andrew Putnam (68) and David Lipsky (69).