Not unlike birth, or the end of some other form of captivity, for two and a half hours he had been protected from all that now suddenly hit him: The noise, the lights, the people, the dread. He was, in that moment, the released prisoner wondering why everyone on the streets is in such a hurry, or indeed the newborn unwittingly pushed into a world of pursed lips, wide eyes, shrill voices, and mobile phones.

Just minutes ago, too, his world had been so different. The room had been quiet and he was cocooned, warm. He was shielded from the chaos soon to come and knew only that its arrival would be announced by a sudden knock at the door from the fist of an outsider. It was then, when hearing this knock at 9:46 p.m., he would understand that it was time and that he must exit the changing room. It was then, to cope, he would try to call upon all his experience and his familiarity with this process.

Only on this occasion in May 2014, both George Groves and his opponent, Carl Froch, walked a path without footprints, neither having previously boxed in front of 80,000 fans. All they had, by way of a guide, was a football pitch, in the middle of which they would meet and where the noise of 80,000 people would quickly fade, leaving only a ring and a referee inside Wembley Stadium.

To get there required Groves going from changing room to corridor to parking lot to pitch. It also required him having to listen to two ringwalk songs, rather than just one, and even board a red double-decker bus, which Groves’ management team had arranged to transport him from the parking lot onto the pitch.

It was, in fact, while waiting for this bus, that the rest of his team in the parking lot were implored to go on ahead, or start walking. “F*ck him up, George,” I then heard one of the 80,000 fans shout from the tier above us, presumably having got his first glimpse of Groves in the flesh. Meanwhile, in the exact same section another man could be heard saying, “George, you’re getting knocked the f*ck out, mate,” which was a comment that not only stayed with me as I headed to ringside, but offered a clear indication of what the fighter himself could expect when making the same walk. It was not just a ring walk, alas, but instead a dizzying walk to the gallows, during which you saw only the deranged, twisted faces of inmates, their heads squeezed between bars, and heard only the stamping of feet and the rumbling of stomachs.

“For whatever reason it was decided we should be excited about the fight with Froch, and everybody was,” Groves would later say. “Everybody came to watch and it was a massive, massive event. It’s hard to put a finger on just how big it was because I was in the middle of it. I was in the eye of the storm and, as a fighter, you don’t even realize there’s a storm until afterward.”

A couple of weeks after the storm, Eddie Hearn, its promoter, was in his Brentwood office still basking in the glory of what he had managed to pull off. By that stage puffed-out cheeks had deflated, the euphoria had started to wane, and all he had left was the debris and a comedown with which anybody accustomed to great highs will be familiar. It was, as they all are, a painful and prolonged sort of comedown, one signified by the assortment of event programs, T-shirts, and unused laminated credentials and wristbands strewn across Hearn’s office floor. These, in many ways, were his empty bottles, each a reminder of what he had done, where he had been, and the fun he had, and each had a way of returning him to that time and delaying whatever he should have now been doing in the present. He had, after all, other events to plan, other fights to make, other fighters to nurture. Yet nothing, it appeared, could compare to what had just passed.

To escape, Hearn that day entered his father’s office, where he discovered different kinds of reminders. In this room, nothing like his own, there were ostentatious chandeliers and wall sconces, plush leather sofas and beautifully-crafted ornaments, plus family photos, vases, and trophies on various ledges. There were also images of Barry, the father, alongside Chris Eubank and Nigel Benn, his Froch and Groves, both of whom helped define Hearn as a promoter over the course of two fights they shared in the '90s. He even possessed the official scorecards from their 1990 encounter, framed and on the wall, as well as a picture of Eubank nailing Benn with a jab. “Funnily enough, me and the old man were talking about the financials of Benn-Eubank II a little while back,” Hearn said. “It was great to compare them to Froch-Groves II. We went through the finances and the revenues and then we talked purses.”

According to a report in the Daily Mail, the 2014 rematch between Froch and Groves was at the time declared the highest-grossing fight on British soil in history, with the largest ever purse: £10 million. (Froch taking home £8 million and Groves £2 million.) In addition, the newspaper’s analysis of the finances showed that the total income from the night was in excess of £22 million, more than any other fight in Britain, while the official Wembley Stadium crowd of 77,000 — rounded up at every turn by Froch — beat the previous British record of just over 70,000, set in 1933 when Jack Petersen beat Jack Doyle at White City. Gate receipts were reported as £6 million, and the pay-per-view sales on Sky Sports Box Office surpassed the 900,000 mark, ensuring, at a price of £16.95, the event would provide a UK take of just over £15m. The international television take, meanwhile, was around $1 million (£580,000), and then there was sponsorship, which poured around £250,000 into the pot, and merchandise and hospitality sales, which added £250,000 to a grand total of £22.3 million.

Benn-Eubank II, very much the template, had also ended up in a football stadium: Old Trafford, the home of Manchester United. Unlike Froch-Groves II, however, it was not an immediate rematch, coming instead three years after the pair’s first fight, and the 42,000 fans inside Old Trafford were ultimately left frustrated when the rematch ended in a draw.

“Wembley had that big-fight feel,” said Hearn, preferring to talk about his baby. “Everybody was dolled up and it was a proper moment, an event, a night out. Yeah, you still get your hardcore boxing fans and your working-class fans, but it was bigger than just that. There were a lot of non-boxing fans there. People would tweet me to say it was the best night of their life and then send me pictures of their seat. They were right at the very top and could barely see the ring.”

Hearn paused to ask someone for a cup of coffee. Big fight hangovers were the worst. “As a fighter,” he said, “when you walk into a packed arena for the first time, that buzz goes a little bit each time you make the same walk thereafter. Next time it’s less exciting and you’re less nervous. And that’s the same with a promoter.

“But then you go to Wembley and it’s a different feeling altogether. How do you top Wembley? Nothing’s ever going to top that. Not for the next year at least. That’s when you’ve got to be a professional and a realist and say to yourself, ‘Easy now, you can’t do something like that every few months.’”

In the 10 years since that night at Wembley Stadium there have been many return visits and there has been a real push to make stadium fights in Great Britain the norm, or at least a semi-regular occurrence. This has seen other stadiums around the country erect rings in the middle of their pitches and beckon tens of thousands of fans to their doors to witness not a kickabout but a punch-up. Anthony Joshua alone has now boxed at Wembley Stadium a total of four times — including his sixth pro fight, which found a place on the undercard of Froch-Groves II — and he has also twice fought at Cardiff’s Principality Stadium and once at the Tottenham Hotspur Stadium in north London. With Joshua, Hearn had more than just a stadium fight, you see. He had a stadium fighter. He had someone around whom stadium fights could be built and with whom stadium fights could become synonymous.

That, for Hearn, was forever the dream, and the next time I visited him at his father’s Brentwood mansion, almost three years after Froch-Groves II, it was all coming together. He was that afternoon ready to announce, via press release, that the ticket allocation for an April 29 heavyweight title fight between Anthony Joshua and Wladimir Klitschko at Wembley Stadium had been lifted from 80,000 to 90,000 (due to a safety clearance from the Mayor of London, Sadiq Khan) and, like any addict whose tolerance has increased, Hearn wanted more, more, more. “When we sold the final ticket for Joshua-Klitschko, there were 34,000 people in the online queue who weren’t able to get tickets,” he said, shaking his head in disbelief. “Which tells you we probably could have sold it out again immediately.”

It told us, too, how boxing itself had in recent years changed, as both a business and an attraction, and how its ever-evolving image had now led us to this point. Gone, it seemed, was the era of Friday night fights in leisure centers between boys next door. The dry ice and lasers. The garish belts. The undercard bouts watched only by plastic seats. Now, in 2017, the smell of chlorine had been replaced by "Sweet Caroline" and cocaine.

“The success has come from taking the chances to do bigger shows,” said Hearn. “We’ve increased the hype and the perception of The Big Event. That’s the art of promoting. You have to make people feel like they have to be at an event and can’t miss it for anything. Once you’ve got that, you’ve mastered it.

“You can’t do that for every event, mind. Sometimes you get it half-right and you get a half-full arena. But the difference is the television product. When you used to tune into 'Friday Fight Night' on Sky Sports, the event would take place at somewhere like Huddersfield leisure centre and there would be 700 people spread around watching a Commonwealth title fight between a Ghanaian and a Brit, with an eight-rounder as chief support. How do you expect to grow the sport based on that product?

“Now when you tune in, you’re seeing packed arenas, people dressed up, and people dancing to music and having a great time, as well as boxers who are familiar to you because they have been built. Good fights, longer shows, and bigger cards. It’s just a progression. It’s a much better product now and that’s why you are seeing more interest in the sport. It’s sexy right now.”

Perhaps the true mark of any trailblazer, Joshua was kind enough to leave the stadium door ajar once he had left. This allowed not only fellow fighters to see Wembley as a viable option, but also, and more importantly, other stadiums began to see boxing as a viable option in terms of generating revenue.

Groves, for example, finally got his hands on a world title at Sheffield United’s Bramall Lane in 2017, when he defeated Fedor Chudinov on the same night that Kell Brook, the Sheffield native, was beaten up by Errol Spence. The year before that Tony Bellew won a WBC cruiserweight title by knocking out Ilunga Makabu at Goodison Park, where he often watches Everton play, and Josh Warrington, in 2018, became IBF featherweight champion at Elland Road, home of his beloved Leeds United. More recently we have seen Chris Billam-Smith, a diehard AFC Bournemouth fan, win the WBO cruiserweight belt at their Vitality Stadium, fulfilling two life goals in one fell swoop.

“On the Friday night we did the ring walk rehearsals, and I went and sat in my old season ticket seat and basically just let myself get a little bit emotional,” said Billam-Smith. “I was sitting there looking at the pitch thinking, 'I used to sit in this seat chanting the players’ names, and now somebody is going to be sitting here chanting my name.'

“To then do the actual ring walk itself, I just had to remain focused and in the zone. I could let myself get emotional the night before, but I did that while knowing that I couldn’t let emotion come into play on the night. It had to just be all about business at that point. You can’t box emotionally. That doesn’t end well.

“When I watch it back now, every single time I get goosebumps and a lump in my throat and am nearly reduced to tears. It’s just a moment that is so, so special to me. It is one I am very grateful for.”

In Billam-Smith’s second defense of the title, he returned to a football stadium, only this time it was not the home of AFC Bournemouth but instead Crystal Palace. That was the team whom Richard Riakporhe, his next opponent, happened to support, and Billam-Smith, always open to a new experience, had no qualms about having an away day.

“Because there were mostly football fans there that night, they of course wanted their man to win,” he recalled. “The difference was this: In Bournemouth, I was standing on the stage looking at the old stand I used to sit in as a kid and hearing loads of fans chanting ‘Red Army!’ back at me and cheering for me. Then I stand in front of the Crystal Palace end (before boxing Riakporhe) and they are all booing me, and I can see a couple of people swearing at me and whatnot. I’m just looking at them and thinking, 'Right, give it an hour and you’ll be upset. You’ll be regretting that.'

“Fights at the national stadium are obviously massive, but there’s something different about a stadium fight at the stadium of the team one of the two boxers supports. It’s even more special, I think, in terms of the passion and the atmosphere. We’ve obviously had Wembley fights, but everyone’s an England fan, and everyone’s there supporting the fight rather than one of the two fighters. You get a much greater sense of tribalism when the fight is actually at a team’s ground.”

There it is at last, the word: Tribalism. Meaning different things at different times and in different situations, tribalism can be responsible for both building and destroying, depending on the time and the situation. In boxing, there can be found in tribalism a ready-made following, tickets sold, bums on seats. Yet there is also the other, darker side of it, which football has known for many years and boxing occasionally experiences when it stands too close to the flame.

In 2013, when set to enter Upton Park, the former home of West Ham United, I recall being greeted by the sight of dozens of fans having a fight of their own ahead of settling down to watch David Haye fight Derek Chisora. Just yards from the ground, in fact, these fans could be seen outside a pub throwing pint glasses, chairs, as well as the odd brick, and it wasn’t long before police on horses were summoned to disperse and take back control.

It was, needless to say, a scene as ugly as it was bloody. It was also a stark reminder of what encouraging tribalism and using it as a promotional tool can do. In this instance, coked-up fans of West Ham had clashed with coked-up fans of Millwall, and the only reason the coked-up fans of Millwall had even bothered to turn up that night was because Haye, the heavyweight in the main event, had loosely aligned himself with their club in the hope of capitalizing on tribalism.

Working for him at the time, I was as guilty of this deception as Haye, and all I wanted to do when watching the Millwall and West Ham fans fight over essentially nothing was shout out the window of our passing car, “He has never even watched Millwall play!” But, of course, in light of the projectiles, it made no sense to open a window at that particular time. Nor would these fans, in their current state, have understood someone explaining how an interest in a football club, even as ersatz interest, could, for a boxer, be commercially and financially beneficial.

“From a business point of view, and from the promoter’s point of view, it’s probably easier to sell tickets because the database is there for the fans and they know a lot of the club’s season ticket holders are going to go because there’s a novelty to it,” said Billam-Smith. “It’s never been done at Bournemouth, it’s never been done at Selhurst Park, and that means it’s one of those occasions where you want to say, ‘Yeah, I was there.’ Down in Bournemouth, specifically, there hasn’t been a lot of boxing in recent years and suddenly it’s getting a bit of a resurgence and the people in the community want to be part of that.

“It’s the same for these Wembley fights. Joshua versus Daniel Dubois, for example, was a fight between two British heavyweights at Wembley and people would have wanted to say, ‘I was there.’ That’s why these stadium fights feel like special nights, because they are different from what we see as normal boxing events.

“The football clubs know this and they want to get involved too. They see one club do it and now they want to do it as well. We’ve seen Barnsley, Bournemouth, and Crystal Palace all host fights recently and they’ve all done it in slightly different ways. The fans turn out every time because it’s a new experience. The whole town gets behind the football club when the club is in a smaller area, and that means that if there is an event at the stadium, whether it’s a music gig or a boxing match, you’re almost guaranteed to sell tickets and attract interest.”

As Groves was helped to his feet and provided an oxygen mask on his stool in 2014, we soon came to learn the kind of interest it attracts, a stadium fight. We came to realize that special nights in big stadiums attract a special kind of interest and a special kind of person.

“Did you enjoy it?” said one of two women to the right of press row, careful not to let the falling ticker-tape spoil her dress. “Yes, it was OK, I suppose,” replied her friend, using her phone to take a picture of Froch, the night’s victor. “I would have liked to see some more hits, though. He got hit once and then that was it.”

On that point they agreed. “Yes,” said the first woman. “I’d have liked to see him take a few more big hits before going down as well. It happened very fast. Too fast really.”