Besides the U.S. Open, in 2016 Johnson won the WGC-Bridgestone (a World Golf Championship event) and the BMW Championship, part of the Tour's FedEx Cup playoffs.
Rahm, at age 23, is now the fourth-youngest player to ever crack the top 3 of the world rankings.
That proved to be only more fuel for him. "More for myself and confidence, after what happened in Shanghai, I wanted to prove to myself that I still. that ain't going to happen again".
Instead, he produced a round that was entertaining even though the tournament was never in doubt.
Johnson holed a 65-yard wedge shot down the hill and up the green for an eagle, and he powered his way to birdies on the par 5s at Kapalua for a 7-under 66 to build a two-shot lead over Brian Harman going into the final round at the Sentry Tournament of Champions. But winning won't come easy for Johnson with the likes of Jon Rahm, Rickie Fowler and Jason Dufner all within five shots of the lead.
He gave his challengers a glimmer of hope when he dropped a shot at the short 11th hole when his tee shot found the bunker, but recovered strongly at the next, nearly holing his tee shot at the 433-yard par four 12th hole. "I know exactly where I want it to come down out of the air, and it did".
"So I knew it was going to be pretty good I just didn't think I was going to have a tap-in".
He heard cheering from the green.
When informed how close it was by Golf Channel reporter Jim "Bones" Mackay, Johnson told him he caught it a little thin.
That stretched his lead to seven shots, and the rout was on.
The world No 1 assumed control on the front nine with three birdies in four holes starting on the third before completing a superb outward 32 with another birdie at the ninth. Johnson went low on Saturday with a blistering 66.
Dustin Johnson finds the flawless way to hit the top of the leaderboard at the Sentry Tournament of Champions as he holes a 70-yard pitch for eagle.
"I got off to a rough start, bogeyed three and four from the middle of the fairway", Johnson said.