The curse of the iconic sporting parent. Accidental, yet real. Decades of evidence show how difficult it is for the offspring of those who have scaled the greatest heights in sport to replicate those achievements. Until Sunday and a stunning finale at Royal Birkdale, Ryan Fox would always be known in New Zealand as the son of Grant. Fox smiles when asked whether the claiming of the 154th Open Championship means he has finally forged his own reputation for greatness. “I can plead a pretty good case for that,” he replies.

“I have two Claret Jugs [one real, one replica] sitting at home so it is real but it certainly doesn’t feel that way yet. I can’t quite believe it. My wife and I have looked at each other quite a lot over the last few days and buzzed out a little bit saying: ‘What the hell just happened?’ It is crazy.”

Fox’s journey has always been distinct. His grandfather Merv Wallace captained New Zealand at cricket. Grant’s fly-half performances and goal-kicking excellence as a World Cup-winning All Black mean he is revered. Ryan dabbled with both sports before landing on golf. “I didn’t have the mental strength to play cricket,” he says. “I was the guy who got to 30 really quickly then got out. If T20 was around back then, I would have been pretty good at it.”

Crucially, he was always comfortable in his own skin and his own movie. Winning the Open, his first major, has elevated Fox’s own status in a land he still adores.

“I grew up with Dad being stopped in the street,” he says. “When I played rugby it was hard because I was always directly compared to him. I was not very smart; played the same position and tried to kick goals. I didn’t help myself there.

“I never had any pressure to succeed in sport. It was just what I wanted to do. I loved sport, grew up with sport, wanted to play sport. When I started to do well in amateur golf there was a little bit more attention because of who Dad was but that never bothered me.

“I don’t know if it is genetic or learned but there has to be something there. Dad caddied for me a lot when I was an amateur and early in my professional career. Having someone who dealt with pressure like he did, kicking goals, translates pretty well into golf. Both are about routines, the ball not moving and starting everything yourself. I always had a sports psychologist on call 24/7. I wasn’t always great at listening but I think enough of it made it through.

“Winning the inaugural World Cup, with how rugby-mad New Zealand is, still feels pretty hard to beat. You can’t really compare it all [to an Open win]. Playing cricket for New Zealand in the 1940s and 50s was a big deal, they didn’t play a lot of Test matches back then but my grandfather had an incredible career. Someone will try to debate all this. I just hope what happened last weekend is a pretty cool thing in general for sport in New Zealand.”

Indeed it is. This is Ryan’s own tale. We speak as Fox is about to board a flight from Florida back to Auckland, a surprise visit with the Claret Jug as hand luggage. “It will be a whirlwind trip and really sweet,” he says. “We didn’t even let New Zealand know we were flying back. I wasn’t going to play over the next couple of weeks and it would have seemed strange sitting in Florida when my peers were playing in different parts of the country. It felt like the ideal time to share this with friends, family and the media at home while it is still really fresh. I had planned to go home in late November but it would have been anticlimactic.

“I have a big lineup of mates who are keen to drink something out of the Claret Jug. Dad is keen to do the same, a rugby tradition is drinking out of trophies. I may only get one chance with it so it feels like I should show it off and take it around. I want to enjoy this as much as possible. I think my life is going to be a bit different in New Zealand now but that is all part of this.

“I vividly remember Michael Campbell winning the US Open in 2005. The whole country stopped. I was a golf fan and it was the greatest thing I ever saw. It is crazy to think a similar thing has happened to me now.”

Bumps appeared on Fox’s path towards Open glory. Despite seeming a natural links player – he has competed at the Irish Open and won the Dunhill Links Championship – Fox’s record in the oldest major of all was average, until Birkdale. “I could never put four rounds together,” he explains. “You could argue I still haven’t together because Thursday was pretty average. But I am not complaining.” Fox sat two over par and seven from the lead after 18 holes.

Fast forward to Sunday afternoon and the 15th, a treacherous par three. Fox’s iron shot rebounds from the bunker face to a horrible position under the sand trap’s back lip. The golfing gods were testing a player who had waded into uncharted territory.

“It was a yard away from being perfect,” says Fox. “Links golf is funny like that. I knew before I got to the ball that it wasn’t any good. I could tell from the reaction of the on-course commentators. I was almost glad it was so close to the lip that I couldn’t even try to hit it out. You could make yourself look really silly if you try to take one of those shots on, on your knees under that pressure.”

Fox hit his ball backwards, walking off with a bogey four that enhanced an already positive mindset. He was helped, perhaps, by the level of focus elsewhere. Bryson DeChambeau captured eyeballs. So, too, did Tommy Fleetwood. By the time crowds flocked to see Fox’s finish, he was so ensconced in a bubble, the size of the gallery did not matter.

The 18th was the hole of Fox’s life. A 330-yard drive, an approach to just inside 12ft and a putt sunk with authority. He looked so calm. “I remember everything, it just feels like I didn’t do it,” he says. “It doesn’t make sense if I try to put myself back there. It is like an out‑of-body experience.

“I was a nervous wreck over the final putt. My hands were shaking and I almost had to talk myself down after getting to the green and realising I had a putt to win the Open. I am not quite sure how I did it.”

Fox’s victory received widespread acclaim. His golf style is simple, his unfussy attitude so endearing. The surfing legend Kelly Slater has been in touch with congratulations. “I got a message from Ronan Keating, which my mum was pretty excited about,” Fox adds. “It has been surreal and I have not even got halfway through my emails. I reply to some people then check my phone again and have more messages than I started with. The support has been incredible.

“The greatest insight came from Justin Thomas. He congratulated me but also offered me advice about trying to remember every little detail because you never know when you will want to draw on it. I thought that was an awesome little nugget, from someone who has been through it.”

A perhaps cruel but regular theme of elite golf is that when a player wins a major, coverage turns towards whether they can do it again. Winners of more than one earn extra kudos. “My caddie said it to me best on Sunday night after we had a few drinks. ‘Foxy, you may only ever have one putt to win a major and you holed it,’” Fox says. “I know I can do it and I would love to put myself in that position again. If I don’t, I am one from one.

“I wouldn’t have thought in my wildest dreams I could achieve all this. Hopefully there is a little bit more left but if there isn’t, I can be incredibly proud.” As can his nation. Ryan Fox has etched his own name in the history books.