Xander Schauffele wins the PGA Championship and his first major title after holding off Bryson DeChambeau in thrilling final day at Valhalla

Neither a mad scientist nor the monkey on his own back could prevent Xander Schauffele from taking the hardest step in golf on Saturday night. After all those near misses, he is finally a major champion.

On no fewer than 12 occasions he had finished in the top 10 in one of his sport's big four, so how fitting that he should win the 106th US PGA Championship by the skin of his nose in the home city of the Kentucky Derby.

And what a race it was, for which we must credit that bonkers maverick Bryson DeChambeau, who tore Valhalla to pieces with irons produced by his 3D printer. At 20 under par he had equalled the lowest ever score in major history, but that was a status he held for barely half an hour, because along came Schauffele. With a six-foot birdie putt at the last, he won by a single stroke.

Exactly a week had passed since he coughed up a good lead to Rory McIlroy on the final day at Quail Hollow, which came with all the reminders that he had not won on the PGA Tour for almost two years. Look at them seven days on – McIlroy entered the backdoor for 12th, Schauffele entered the champions' circle.

With two fists clenched and tears in his eyes, he had stopped those nagging conversations about the best players to never claim a big pot. Given the all-round strength of his game, the 30-year-old would also be a solid candidate to push on and take more – he doesn't look like a one-hit wonder.

But he did have to go the hard way in his closing 65. It only involved a single bogey at the 10th, but the challenge was found in the quality of those in pursuit. We should mention Viktor Hovland first, because a couple of weeks ago he was unsure if he would compete, such was the dire state of his game, but he hastily reunited with Joe Mayo, the coach he sacked late last year and his resurgence here was remarkable.

A three-putt at the last killed his chances with a 66, so 19 under par, and he finished three back of Schauffele and one clear of Belgium's Thomas Detry and Collin Morikawa, who started in the final pairing and stalled with a 71. Justin Rose and Shane Lowry tied on 14 under after an excellent week, with Scottie Scheffler one rung below alongside Bob MacIntyre. In Scheffler's context, it says everything that he can visit a jail cell and still tie for eighth.

The astonishing number of players in double digits under par – a record 25 - speaks of the easy conditions, but also the heat of the competition, because clearly anyone could go on a tear.

By the end, DeChambeau almost forced a play-off, but needing a birdie on the last, Schauffele got up and down from 36 yards, sealing victory with a six footer than caught the edge and dropped. In technical terms, that closing drama was indicative of his day, because his driving, so brilliant all week, was loose with so much at stake and he would hit only six of 14 fairways. In other words, he needed to grind and scramble and did so exceptionally well, either for par or better, including the up-and-down birdie from dense greenside rough at the driveable par-four fourth hole.

As ever, the drama didn't commence in earnest until the back nine. By then it was a three-horse race and one that had been led almost exclusively by Schauffele, as had the entire tournament. Barring his starting position on 15 under alongside Morikawa, and a brief moment when Sahith Theegala birdied the opening hole, he was out own all the way to the 10th hole, albeit never by more than two.

Rounding the turn in 31, and 19 under par, Schauffele stepped on that tee one ahead of Hovland and two clear of DeChambeau. That was when he finally hit a bump, with the origin of his difficulties coming from an attempt to reach the par five in two from the fairway bunker. His club? A three wood – it was golf but not as most of us know it.

Alas, that was a misadventure led to dense greenside rough, an overhit pitch, and under-hit chip and eventually a bogey six.

The blow was quickly compounded – Hovland, two groups ahead, had already birdied 12 and then dropped a 15ft bomb on 13 to pull level with Schauffele for the first time all day at 19 under. The Norwegian had a hot putter in his hand - would Schauffele have the mettle for a fight?

His response was the stuff of champions and he carded consecutive birdies to pull in front again, but that's when the challenge of DeChambeau accelerated. Golf's most quirky thinker would reach 19 under and just one behind Schauffele after some outrageously good fortune at 16.

His snap-hook from the tee had clattered the trees but bounced back to the fairway, which preceded the 30-year-old launching an eight iron a monstrous 219 yards to three feet. Birdie collected, he was in the same boat as Hovland in needing one more birdie at the very least.

Playing the par-five 18th, DeChambeau trickled in a 10-footer to do just that and burst into flurry of air-punches after his 64. A moment later, Hovland, from similar distance, three-putted and deserved better than a first bogey and a 66.

Over to Schauffele, who was once again tied at the top and had found a horrible spot in a fairway bunker with his drive on 17. He was playing his own demons now and after fanning his recovery to the right of the green, he chipped to three feet to save par. The equation from there was simple and also complicated – birdie the last and he was champion.

He went the hard way, with a drive that came up a foot short of the fairway bunker. That left the ball above his feet, which were planted in the trap, and his approach came up short of the green, 36 yards from the flag. The pitch left a six foot putt for all the marbles – he nailed it.