Moriwaka, one of the bright young stars of American golf and already ranked No. 12 in the world prior to his win, closed with a sensational 64 to blow everyone away on the final day at TPC Harding Park.

His chip-in for birdie at the 14th set it all up, but it was his tee shot at the 270-metre par-four 16th hole that will live in the memory, one of the best shots in major championship history.

Already leading by a shot but refusing to consider caution, he blasted it on to the front of the green and up to two metres from the flag, rolled in his left-to-right sliding putt for eagle, and put up the parachute for the final two holes to win by two shots at 13-under par.

It marks the arrival of a new superstar of the game.

Morikawa, a native Californian who has Japanese and Chinese heritage, joins Jack Nicklaus, Tiger Woods and Rory McIlroy as players who won the PGA Championship at his age. Playing in the second-last group and starting two shots back from Dustin Johnson, he jumped out of a pack that at one point included six joint leaders and another cluster just a shot back.

As for Day, he could not have done much more in finishing tied-fourth. He shot 66, four-under par, without a single bogey. In truth, he hardly made a mistake, from the time he rolled in his birdie putt on the first, to the long bomb for birdie at the par-three 11th that pitched him into a share of the lead at 10-under par, to the closing stretch.

All week, he looked to be back to the type of form that saw him reach No. 1 in the world late in 2015.

Day’s momentum was strong on the back nine but it was at the short, par-four 16th that he gave ground … with a par. Taking three wood off the tee and trying to slide it on to the front of the green, his ball went straight and into a fairway trap, meaning that he would only make par.

At the par-three 17th he gave himself a chance of birdie but by then, Morikawa had the lead outright, and Day’s putt missed. Knowing he would need birdie at the par-four 18th, Day drove into a fairway trap and then his second shot flew into a greenside bunker, meaning he had to scramble his par.

It was Day’s highest finish in a major championship since the 2016 PGA, when he was runner-up to Jimmy Walker.

Adam Scott also had a good week, especially considering it was his return to tournament golf after five months. Scott carded a two-under par 68 to finish tied-22nd, while fellow-Queenslander Cameron Smith (70 today) finished tied-43rd.

A bunch of players had a hand on the Wanamaker Trophy today, headed by Englishman Paul Casey, one of the best players not to have won a major. Casey (68 today) finished tied second at 11-under par with overnight leader Dustin Johnson, whose long birdie putt at the 72nd hole for a 68 gave him yet another runner-up finish in a major.

The bunch of five tied-fourth included Day, Tony Finau (66 today), Bryson DeChambeau (66) and Matthew Wolff (65) and Scottie Scheffler (68). One other player – Cameron Champ – also touched 10-under to share the lead at one stage.

All of them had their chances but the winner was unequivocal.

Morikawa has won three times on the main tour having turned professional only last year. “It’s amazing. It’s been since I was a little kid, watching everyone growing up, watching these professionals, wanting to do it,” he said.

He is quite some talent.

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