Nerve-less Collin Morikawa shot a scintillating bogey-free final round to clinch the Claret Jug on his Open Championship debut as returning fans soaked up the victory at a sun-drenched Royal St George’s.

The 24-year-old, who won his first major on his US PGA Championship debut last year, becomes the first Open debutant to win since Ben Curtis did so at this course in 2003.

“This is one of the best moments of my life,” he said. “Look at all these fans. To see some of the best crowds I have ever seen, I’m looking forward to making my trip every year.”

Morikawa’s four-under 66 saw him win on 15 under, with 2017 champion Spieth also recording a final-day 66 to finish as his fellow American’s nearest challenger.

US Open champion Jon Rahm birdied four of his last six holes to card a 66 and finish joint third on 11 under with overnight leader Louis Oosthuizen, who closed with a 71.

Scotland’s Robert MacIntyre finished as the top British player in a tie for eighth after a final-day 67 saw him finish at seven under par, two ahead of England’s Paul Casey at five under.

Up to 32,000 spectators flooded through the gates on Sunday and were treated to a blockbuster final round as the only players to make the cut in all four of this year’s men’s majors finished as the top four in Sandwich.

It was a fitting finale at Royal St George’s as the venue belatedly got to hold the 149th edition of golf’s oldest major after last year’s championship was cancelled because of the Covid pandemic.

Morikawa ice cold in searing heat

Shane Lowry’s victory at Royal Portrush two years ago was beginning to feel like it hailed from a different era when sport was locked down and, while six majors have since been played in the US, this was the first to be staged on this side of the Atlantic Ocean since the Irishman’s iconic victory in 2019.

Rain before the tournament thickened up the rough and provided receptive fairways and forgiving greens, but that meant once the wind dropped players were able to shoot low scores on Friday before organisers responded with tricky pin positions for the weekend.

However, it was Oosthuizen who held on to a one-stroke lead heading into Sunday’s final round, looking to record a wire-to-wire victory and win his second Open title.

Morikawa admitted he had little experience of links golf – and recorded his worst result as a professional when finishing joint 71st at last week’s Scottish Open – so the benign conditions perhaps suited the Californian, who is regarded as of one of the game’s finest iron players.

Amid the searing heat on Sunday, the world number four also showed he has the temperament to add further to his major tally.

As three successive birdies dropped for Morikawa he suddenly found himself taking a four-stroke lead as he hit the turn, with Oosthuizen stuttering in the final pairing alongside him.

But the first flicker of emotion from the American came at the 10th when he made a superb up-and-down from the back of the green to save par, fist-pumping in celebration.

By this point the Spieth charge was alive but Morikawa birdied 14 to keep his compatriot at arm’s length and, with roars going off further up the course, saved par again at 15.

From there it was a case of keeping his nerve as the anticipation grew among the excited fans, but that was no trouble for Morikawa who took a two-shot lead down the last and strode on the 18th green to huge applause, moments away from becoming the first man to win on his Open debut in 18 years.

He two-putted for a final par to see out the victory and then waved and clapped the fans packing out the 18th grandstand in fittingly composed fashion.

“I tell everyone I am not the biggest history guy but I want to add myself to history and make memories for myself,” said Morikawa, admitting he will “have a few drinks” from the Claret Jug.

“Everything about this week was very special, to cap it on my caddie’s birthday, even more special.

“I’ve had belief in myself since turning pro that I can do it. When it’s coming to these tournaments, courses and styles that I have never played, I do my homework Monday to Wednesday to know what I need to do.”

Oosthuizen’s dreams turn to nightmares

South African Oosthuizen went to sleep on the first three nights of the championship as The Open leader, but the wait to realise his dream of adding another Claret Jug to the one he won at St Andrews in 2010 continues.

He had only made three bogeys in the whole tournament before his final round but carded as many on Sunday as the tension showed, living out a nightmare seventh hole where he splashed from bunker to bunker either side of the green while Morikawa birdied.

Oosthuizen’s luck almost changed when he hit the pin with his tee shot on the par-three 11th and his ball nearly dropped in for a hole-in-one, instead taking a birdie.

But the 38-year-old has finished runner-up six times in major championships and there was a knowing look of resignation when he bogeyed the 13th.

He did claw one stroke back on the following hole but by that time Morikawa was in full control, with Oosthuizen carding his only over-par round of the week to finish four back.

Spieth rues ‘really dumb mistakes’

After a bogey-bogey finish on Saturday – the latter of which coming when he missed a two-foot putt – it was going to need something special from Spieth to challenge from three strokes back in the final round.

Bogeys at four and six made that task even harder but the three-time major champion sparked into life with an eagle at the par-five seventh and continued his hot streak with birdies either side of the turn.

Spieth has not won a major title since winning The Open at Royal Birkdale in 2017 but when he made successive birdies at 13 and 14 the chatter from fans along the ropes was that perhaps there was a chance he was about to end that drought.

Ultimately Morikawa’s controlled performance down the stretch meant that was beyond his reach, leaving Spieth to rue his mistakes on Saturday.

“I’m proud of going six-under in the last 12 in this golf tournament and putting some pressure on Collin,” said the world number 23.

“From what I’ve heard, since he made a big par save on 10, made a putt up the ridge on 14 and a par save on 15, I needed a break and I didn’t get it from him.

“I did all I could. So I’m upset because I really felt like I played well enough to win and made a couple of really dumb mistakes – like just stepping in and missing on 18 yesterday, not really thinking about it.

“But at the same time, I did everything I could in the past few hours to win this championship.”

Rahm, Brooks Koepka and Dustin Johnson were other players who left themselves with too much ground to make up on the final day.

Spanish world number two Rahm entered the week as the short-odds favourite and followed an opening 71 with rounds of 64, 68 and then a 66, that featured an eagle and four straight birdies.

“It’s easy to think about all the things that could have been better,” he said. “The biggest mistake was that first round.”

Four-time major winner Koepka’s 65 lifted him to joint sixth on eight under but he admitted it was a “back-door top 10” after a 72 on Saturday took him out of contention.

World number one Johnson had a similarly poor third round, his closing 67 lifting him to seven under.