It was a fourth tournament win in just eight starts for the 36-year-old who is clearly playing the finest golf of his life.
In that span he has ticked off victory in the PGA Tour's Tour Championship and also landed a first Green Jacket in the Masters.
His victory at Royal Greens Golf & Country Club did not come without a few worries on the greens, but it was generally another superb performance.
Here's how and why Johnson completed his triumph.
Tee to green class
The current brilliance of Johnson's long game is revealed in his Greens in Regulation stats.
In each of his last three tournaments he's landed an average of 15 out of 18 (83.3%) per round.
And in the Houston Open which preceded that run? A drop to 79.2%, but he ranked first in the field.
Time and again, then, he is avoiding trouble around the greens and if you hit the short grass that often, especially when hitting the vast distances Johnson does, the birdie opportunities will present themselves.
As he said himself after the win: "I felt like I struck it very well all week and I drove it really good. So I gave myself a ton of chances."
All that said, Johnson did not have it all his own way on the (Royal) greens, even concluding: "Very excited but I'm going to have to go home and work on the putting a bit I think."
Together with his brother and caddie Austin he has become an excellent reader of the slopes and yet both looked mystified last week.
The good news is that the rest of the field was in much the same situation - the commentary team reported that many players were talking of the visuals fooling them both in pace and direction.
The secondary good news is that Johnson maintained his patience.
Late in the final round he did sag the shoulders and huff, but it was momentary and did not derail his challenge; he accepted what was happening and this sang froid has clearly been a key to his success since the middle of last year.
His putting might have been a little off last week, but his mindset isn't.
His success in Saudi Arabia is clearly part of a rich vein of form, but it is one which witnessed a bizarre blip.
He began the stretch with a round of 61 and victory in last June's Travelers Championship.
However, he immediately shot 80-80 to miss the cut at the Memorial Tournament and after a 78 to kick off the 3M Open he withdrew.
It seemed the hot golf had been knocked off track, but it was a short term injury-related problem and he bounced back to lead the PGA Championship after 54 holes before finishing second.
In all, his last 12 completed starts around the world have reaped five wins and another four top three finishes.
The relentlessness of his high quality explains the whispers of his current golf being "Tiger-esque".
Horse for the course
"I like the golf course," Johnson said last week, in typically understated manner. "I think it sets up good for me. I've liked it since the first time I came here a couple years ago."
He's not wrong.
He shot a second round 61 on his way to triumph in 2019 and finished second last year.
He's never finished rounds two, three or four outside the top ten, he's never needed more than 68 swings to complete a round, and he has a stroke average on the course of 66.33 (64.33 on Fridays).
Doesn't mind the wind
It's easy to characterize Johnson as a big-hitter and therefore believe there is something one dimensional about him.
However, he has a fine record at Pebble Beach, twice winning there in poor conditions.
It's a track the other Royal Greens winner, Graeme McDowell, has also won on (in the 2010 US Open which Johnson ought, perhaps, to have triumphed in).
The Red Sea in the desert and the Pacific Ocean from the Californian cliff-tops are obviously very different tests, but both men have the capacity to cope with blustery coastal winds which swiftly changes direction, Johnson even referenced as much during the week.
Dealing with a lead
The fact that Rose posted a clubhouse target with a final round 65 was a reminder that Johnson has not always been the surest of closers.
Back in 2017 he had a six shot 54-hole advantage over the field at the HSBC Champions, Rose closed in style, and Johnson stumbled home in second with a 77.
And that US Open he should have won? He was three clear with 18 holes to play before a cataclysmic Sunday 82 left him tied sixth.
Only two seasons ago he was one clear after three rounds of The Heritage and closed with a 77 to end the week outside the top 25.
But he's getting better as a finisher.
The first 14 times he held or shared the 54-hole lead he completed the win six times (42.9%).
His last six conversions have come in nine shots at it (66.6%).
Johnson is enthusiastic about the rest of the season.
"This gives me a lot of confidence going in for the rest of the year," he said afterward. "I'm pleased with how I'm playing and looking forward to the rest of the year."
Johnson is 13/2 with BetFred to successfully defend his Masters title in April.