Johnson got a great roll from his 430-yard tee shot to land within inches of the pin and tapped in for two, with the only blemish on his Sunday card coming on the par-three 11th.
It took a ideal bounce, a flawless route and some wind to help the ball take off ... but couldn't it just roll a few more feet?
In typical nonchalant fashion, he remarked "I hit it a little thin", before grinning and confessing, "I hit it perfectly".
The eight-shot margin of victory was his largest ever, and it was one short of the tournament record set by David Duval since this event moved to Kapalua in 1999.
"I mean I go back over it and talk about it, but as far as how long has it frustrated me or anything, not long".More news: Acer Introduce The Nitro 5 - Designed With Casual Gamers In Mind
Johnson claims he'd forgotten all about China until media reminded him of it.
Johnson, who seized the world No. 1 ranking last February, has now won at least one US tour title for 11 straight years. "And there were times when I putted well but couldn't sink them". Jordan Spieth also won by eight shots in 2016.
Dustin Johnson hit one of the best shots he never saw.
When he was in this sort of mood a year ago he won three straight events at the Genesis Open, World Golf Championships - Mexico Championship and the World Golf Championships - Dell Match Play. "I know exactly where I want it to come down out of the air, and it did. If my mind's wandering and thinking about other things, then I'm not going to have a good day", Johnson said. "First I want to get to 20, then 30 and once there 40", he added. A freak accident knocked him out of the year's first major before play started.
"This week was better than I thought", Matsuyama said. He was consistent and impressive through all four rounds, shooting 69-68-66-65-268.