He became a first-time major winner at TPC Harding in San Francisco last year in front of no fans, leaving some to wonder if he could repeat the feat in front of 32,000 spectators at Royal St George’s.
‘Yes’ was the answer as the 24-year-old Californian produced a polished last-day performance to get his hands on the Claret Jug at the first attempt.
Compatriot Ben Curtis achieved the same feat at the same venue in 2003, but he proved to be a one-hit wonder in the game’s biggest events.
Morikawa has now proved that he won’t end up with such a tag and, on the evidence of this stunning performance in Sandwich, that title haul could well end up being something special.
On a red-hot day in Kent, Morikawa signed off with a 66 to finish with a 15-under-par 265 total, winning by two shots from 2017 champion Jordan Spieth (66), with overnight leader Louis Oosthuizen (71) and US Open champion Jon Rahm (66) two shots further back.
Oosthuizen, who had finished second in the last two majors and six in total since his Claret Jug win in 2010, relinquished his lead after missing the green at the fourth and failing to use the slope how he had intended.
The South African then sent his third shot at the seventh from a bunker on one side of the green to one over the other side, finding a nasty spot in the process.
A two-shot swing there meant Morikawa was the new leader. “That was the turning point,” admitted the evetual winner, who responded by slamming his foot to the board. A majestic approach set up an easy birdie at the next before he then rolled in an 18-footer at the ninth to sprint three ahead.
While nothing really happened for Oosthuizen in the final round, it was Spieth who tried to close down the leader on the back nine.
The Texan had dropped shots at the fourth and sixth before rolling in a 15-footer with a double break for an eagle-3 at the seventh. When he then added four birdies in six holes from the ninth, it was still game on.
Up ahead, Rahm had reeled off four birdies on the spin from the 13th, capping that burst by almost holing his tee shot at the short 16th.
But Morikawa wasn’t to be denied. His fourth birdie of the day at the par-5 14th – he described his caddie getting him to hit a 5-wood off the tee as “the best decision of my life” – gave him a bit of breathing space over the closing holes.
He’s shown when winning that US PGA Championship that he can be a cool customer in the heat of battle in these events and he proved that once again.
“I'm proud of going six-under in the last 12 in this golf tournament and putting some pressure on Collin,” said Spieth as he reflected on his brave bid. It's hard to be upset when I was a couple over through six. I couldn't have really done much more after that point.”
He’d been fizzing, though, after finishing with two three-putt bogeys on Saturday to lose ground at the top of the leaderboard. “The finish yesterday, was about as upset as I've taken a finish of a round to the house,” he said.
“I walked in and I said, ‘is there something that I can break?’ I knew that was so important because I would have been in the final group.”
“I've been in that position a lot of times, and it's a lot nicer when stuff's happening in front of you and you can control. You can still birdie that hole, versus I get off the 16th today and it's like, “well, they could birdie behind, and there's nothing I can do about it now.
“When you're the last to come in you've got the last chance on 18, and I think that's the easiest place to come from, especially when it's easier conditions.”
Taking advantage of that, Brooks Koekpa, Bryson DeChambeau, Xander Schauffele and Rickie Fowler had all earlier carded 65s before the winner, runner-up and Rahm all came in with their 66s.
“It's a good championship,” said Rahm of his effort. “Played really good golf. I think the main part of my game that could have been a little bit better is putting. Not that I'm asking to make every putt, but I really struggled to make putts outside really eight feet.
“Too bad I've ended up just shy. Yeah, but I'm still going to smile because I gave it my all. Finished really, really strong and gave myself the best chance I could.”
On the back of weekend scores of 65 and 67, Bob MacIntyre finished as the leading British player in joint-eighth alongside Dustin Johnson as the world No 1 signed off with a 67 for his seven-under total.
Norwegian Viktor Hovland was in a group on six-under, as was defending champion Shane Lowry. “All in all, it's been a great week,” said the Irishman. “Another good performance in a good tournament. I'm happy with myself and I'm proud of myself.”
He’d just turned in 33, two-under, when second shot at the 10th ended up tight at the bottom of a bunker face, meaning he could only move the next one a few feet. “Just a bad break,” he said later. In the end, he did well to limit the spillage to a bogey.
German Marcel Siem, the man who looked to have enjoyed the week more than anyone as he waved and fist-pumped his way around the course, birdied the last to finish joint-15th o five-under while compatriot Matthias Schmid claimed the Silver Medal for leading amateur on two-over.