On Saturday night, Tyson Fury will walk to the ring at the MGM Grand Hotel in Las Vegas to contest the richest prize in sport when he boxes American Deontay Wilder for the WBC World Heavyweight Title.

Fury will be announced in exalted terms – the Gypsy King, the lineal champion, undefeated – and the hype surrounding the contest rests on the fact that both men have perfect records. ‘We are the only two undefeated warriors in our era,’ Fury said recently. ‘People want to see who is the best.’ John McDermott has good reason to disagree. In September 2009, he boxed Fury for the English Heavyweight Title, in a bout most in the sport think he actually won.

Despite being champion and having the home advantage of the Brentwood Centre, Essex’s McDermott went into the fight as heavy underdog. Fury was eight years younger at 21, had an 8-inch reach advantage, and had knocked out his first seven opponents. McDermott was at 7/2 to win with the bookmakers, Fury the 1/6 favourite. Sky Sports presenter Dave Clark opened the night’s coverage describing Fury as ‘Britain’s next big heavyweight hope,’ asking dismissively, ‘John McDermott, can he impress?‘ There had been some bad blood in the build-up to the bout, with Fury mocking McDermott’s physique with nicknames: ‘McMuffin’, ‘Big Mac’, ‘McDoughnut’ and the like. This only spurred him on, and he felt an over-confident Fury was looking past him.

McDermott had a clear plan and boxed brilliantly. “For John to beat Tyson, it had to be the jab,” his former trainer CJ Hussein remembers. “A tall fighter like Fury walking in was made for John.” And that powerful double-jab, along with the big looping right and jarring left hook, immediately showed signs of unsettling Fury. Fury threw many more punches in the fight, but landed far fewer. He tried to butt heads with McDermott after the bell at the end of the very first round, a sign of the frustration building up inside. He began looking to his corner for direction mid-way through the fourth, and by the break ahead of the tenth and final round, his cornermen were instructing him in clear terms: ‘Get him out of there, Tyson, this round.’ Fury looked exhausted and confused, asking what combination of punches to use.

By then, the odds had completely reversed. McDermott was overwhelming favourite to be crowned champion three minutes later.

In an interview this week, he remembers the fight. “When you are fighting, every exchange you come out knowing if you won it. Every exchange I thought, I won that.” But he is honest that he did not have things all his own way. “Fury has bottle, that is what I will say for him. I hit him hard, and his eyes rolled back. Any other opponent would have gone, but he came back. I know because I’ve been there. It takes real courage.”

When the final bell rang, McDermott turned immediately to his corner to await the decision of the judges. Behind his back, referee Terry O’Connor raised Fury’s hand as the winner.

Fury barely celebrated, perhaps knowing that he had been lucky. The partisan crowd stayed quiet. McDermott did not even know. “My previous fights had been 12 rounds not 10, and three judges’ decisions,” he says. “Maybe the referee has the best seat in the house, but I didn’t even know he was scoring the fight.”

For a fighter not to have been told the rules in his contract is, at best, peculiar, but there was more. Before the fight, McDermott’s camp had insisted that Terry O’Connor must not be the referee. There was history between them going back to O’Connor’s days as a prizefighter in the seventies.

“My dad beat Terry O’Connor in the pros, knocked him out,” McDermott says. “It [the referee] was meant to be Richie Davies, but minutes before the fight they said he was ill, and Terry stepped in. I still have a letter from the Board of Control because we had asked for the ref not to be him.”

McDermott stopped short of accusing O’Connor of cheating, but cannot help but feel their family history influenced him, and not only that night. “I lost every fight when he was the referee.”

As the ring announcer confirmed the result, 98-92 in Fury’s favour – according to O’Connor McDermott had won just two of the ten rounds – the crowd booed. Sky Sports expert Jim Watt wondered out loud if the referee had got the names mixed up, so sure he was that McDermott had won. Commentator Adam Smith roared that every journalist at ringside agreed with Watt.

McDermott’s promoter Frank Maloney – who suffered a mild heart attack at ringside such was the stress – was candid: O’Connor was a ‘disgrace to British boxing’ and the result ‘daylight robbery.’

Sitting on the ring apron waiting to be interviewed, McDermott cut a desperate figure. It is usual in boxing for both fighters to claim victory after a close contest, but there was no doubt as he poured his emotions out. As Hussein had told me, “John was not made for the media, but he spoke from the heart.”

Through an emotional crack in his voice McDermott ached. ‘It’s absolutely ridiculous. What have I got to do to win here? I’m a nice, genuine guy, and I get penalised for it.’ It was not only that night that McDermott got the rough end of a decision.

He was coming off the back of two controversial defeats to veteran Danny Williams, and it seemed his face simply did not fit in the murky political mess of boxing. He was quiet, interested in painting and sculpture, and intelligent.

Nicknamed ‘Big Bad John’, his looks were deceptive: his physique closer to that of a bouncer than an athlete. “I trained until I couldn’t anymore,” he told me. “I tried diets, protein shakes, and could run 15 miles. My body just didn’t change. People don’t realise what it takes.”

As he relived the moments with me, I felt the hurt for him. “I was so devastated,” he laments. “I just kept thinking they’re not going to let me through.”

Hussein, is in no doubt the establishment took against his fighter. “For John it was the way he looked,” he says. “He didn’t look good, but he was fit. His physique just wasn’t impressive.”

And throughout his career, McDermott had to silence his own doubts. “I was always very nervous,” he says. “Before a fight I honestly did not care whether I lived or died in there. When the bell went, it all went away. I was a different person.”

Ringside that night the boxers agreed a rematch. The Board changed the rules for English Title fights; this one would be a full 12 rounds, scored by three independent judges, and Terry O’Connor would not be officiating.

But negotiations dragged on, and the return only eventually happened nine months later. “By the time the second fight came around I had glandular fever,” McDermott recounts. “I was getting married, had a young daughter. The fight was called off two or three times. I had been training for months paying sparring partners, and I had no money.”

And not for the last time in a fight involving Fury, there was more last-minute controversy. “One hour before, his team changed their gloves to Reyes, which are built to do serious damage,” a breach of contract McDermott claims.

At that point, his new trainer, Jim McDonnell, told him to pull out of the fight, but McDermott says that on the spot the promoters threatened to sue him for the financial losses they would incur. Broke and ill, he fought well again, but lost, exhausted, in the ninth round.

McDermott retired from boxing in 2013, three times challenger for the British Title, with a professional record of 28 wins and 8 defeats. Married with three daughters, he now works in construction.

“In a few weeks my contract runs out and I do not know what I will do,” he told me with humour. “Maybe I will go back into boxing. You never know.”

I ask him about the fight this weekend. He’s still a boxing fan, he says, and he will probably watch it, if he is awake when things get underway around 4:00 AM on Sunday.

He feels no bitterness about that night in 2009, and admires Fury’s achievements since. “There is no point in killing yourself over it. I was a seasoned pro and he was a novice. He did well to stay with me. I knew then he would be something special. He’s a nice enough bloke who has been through a lot. I want him to win, but I don’t think he will.”

Did Fury ever admit to him in private that the decision was wrong? “No fighter will ever say that they lost,” he said, as though I was stupid to ask. “But John Fury [Tyson’s father] did say, ‘You won that, my lad didn’t win it.’ which was good of him.”

Hussein is less diplomatic. “I am still bitter,” he says. “Will I be watching? No. As a trainer, I beat him. I don’t care who wins.”

McDermott holds no grudge, and refuses to be drawn on who it was who stopped him from breaking through to the next level of British heavyweight boxing.

But, for me he was denied that moment: having his hand raised in the ring as the champion who had trounced the rising star.

And he deserves to be able to sit watching in the early hours of Sunday morning, amid the inevitable talk of undefeated warriors and perfect records, regaling his daughters with tales of the day he beat the champ.