If it was a rollercoaster for England as a whole – as they somehow managed to squander New Zealand’s post-lunch scoreline of 45 for 7 to finish a 17-wicket day with the prospect of a first-innings lead in doubt – then Potts’ own performance epitomised their wild swings in fortune.

A wicket with his fifth ball in Tests, and that of New Zealand’s captain Kane Williamson too; two nerve-testing catches on the fine leg boundary; a worrying moment of cramp that caused him to leave the field midway through his final over, and finally a second-ball duck in his maiden innings, as Trent Boult bombed his gloves with a bouncer that ballooned to slip. It’s been quite the ride already, and his career is only 78 overs old.

“We’ve had an eventful day,” Potts said, as England limped to the close still in deficit. “We’ve come to entertain, that’s our first and foremost thing, and it’s been an entertaining day of cricket, and it’s one that I’ve thoroughly enjoyed. I know the team’s enjoyed it. And we’re still in a contest to win a game of Test cricket here.

“We’ve got three wickets left in hand, we’re going to attack the day tomorrow and then when we get the opportunity to bowl, we’re going to put it in the same areas we’ve put it in today and we’re going to pick them up and hopefully try to win the game of Test cricket.

“We’re going to throw our punches. Personally I think it’s very, very entertaining, I think it’s what we all want to see. We want to exchange blows, and if they throw us two, we’ll throw them four. So we’ll just see what happens.”

It was a remarkably composed assessment of the first day of England’s new era under Brendon McCullum and Ben Stokes, Potts’ Durham team-mate. But it was also in keeping with what is already a remarkable season for Potts, who demanded selection for this contest with the stand-out stats of 35 wickets at 18.57, including four hauls of six wickets or more, and has now improved his season’s first-class average to 39 at 17.

“I’ve wanted the approach that I’ve taken towards my Durham cricket, and I see no change in the way I’m looking to approach it,” he said. “Maybe the outcome’s slightly different – a little bit of a bigger scale, a bigger stage – but I’m personally trying to bring the same kind of gameplan to the forefront, and that’s one of the assets that’s got me picked, and hopefully deliver on that.”

Perhaps nothing displayed his sang froid better than his two steepling catches in the afternoon session, both of them top-edged pulls off James Anderson that could have given him far too much time to think about the consequences. But, having already done his utmost to block out the acclaim from an already supportive crowd, he was able to set himself well and pocket them with ease.

“The first one I didn’t see,” he said. “I looked up and thought ‘oh no, can it not go to deep square instead of fine leg’. But when the ball goes up, I’ll always put my hand forward and try to catch the ball. It’s all about how [the crowd] affects you. I don’t know how I will react if I gee the crowd up. The body does weird things. Especially on this stage. It’s nice to know I have the country’s support but there’s no need to get distracted. I was focused on the job at hand.”

Potts did, however, permit himself a moment of pure joy when, having brought into the attack early by Stokes, he struck before his first over was complete, as Williamson pressed forward to a good length on off, and Ben Foakes stooped behind the stumps to deliver England’s fourth and most-prized wicket of a wild first ten overs.

“Honestly, I felt very composed before the first ball, and then I bowled a long-hop second ball and I was very nervous after that,” Potts said. “But I just focused on putting it in a good area, hitting the pitch hard with a bit of wobble on it, and that ball nipped off a good length, drawing a bit of a false shot, with a nice catch from Foakesy.

“I mean, absolute elation,” he added. “A Test debut at the home of cricket, in the pinnacle format of cricket, and then to get the New Zealand captain out fifth ball. Absolutely over the moon and can’t put into words really how that feels. I know it probably meant an awful lot to me, and an awful lot to my family as well.”

“We had them nine-down and the calves were barking at me a little bit,” Potts said. “An eight-over spell, a bit of soft ground and me probably throwing 110, 115% into it without realising. A bit of nerves probably takes its toll on the body.

“I could have gone for five. I told Stokesy I could keep on bowling. I am the first person to keep on battling through things at Durham. But it was more of a case of making sure you don’t pull anything or do anything stupid,” he added. “I’m trying to get myself right and win a Test, rather than us be a bowler down because I’ve pulled a calf trying to take five.

“Stokesy took the decision off me and said ‘get off the pitch, go rest and we’ll get the last wicket’. He said ‘you make sure you’re ready for the second innings’ because that is crucial, that’s where the endgame is going to be.”

Even though his first day of England cricket didn’t end with quite the dominance it had promised, Potts was phlegmatic about the ebbs and flows already experienced.

“Look, you don’t have a gameplan set in stone, you know gameplans don’t always go the way they should, and we have to be able to adapt and that’s what we’re going to have to do,” he said. “Yes, it was a rollercoaster, yes I wanted to take the boots off and just put the feet up. But the battleplan’s always changing, and we’re constantly changing on the move.

“The way we want to play our cricket is entertaining, we want to be on the forefront of it, we want to be on the front foot, and I think that’s the way we’re going to go with it.”