This shocking footage shows the moment former professional boxer Julius Francis knocked out a man with a single punch while working as a security guard outside BOXPARK at Wembley Stadium.

The former British heavyweight champion, 57, was dismissed inside two rounds by Mike Tyson in their Manchester showdown in January 2000 - snapping a three-fight winning streak in the process.

Francis, who is also a grandfather, walked away from boxing with a 23-24-1 record.

He has spent the past few years working as a security guard to support his family.

And now Francis has gone viral after footage emerged on social media of him knocking out a man with a single punch during a street brawl.

A group of men were filmed having a dispute outside BOXPARK in Wembley, London on June 14.

One of them, a man wearing a blue durag, appears to be behaving in an aggressive manner, as footage shows him taking a couple of swings at a group of men standing behind the barriers.

The security guard can be seen backing away from the other man, who continues to act aggressively, as he tries to take stock of what is going on.

WATCH: Former British heavyweight champion Julius Francis shows the power is the last thing to go working security at Wembley

Check out the video below...

After trying his best to defuse the situation, Francis coolly delivers a single punch to the other man's face, sending him to the ground.

The shocking footage has gone viral and racked up over 60,000 likes on Twitter in under 24 hours.

During his career, Francis faced off against the likes of Audley Harrison, Vitali Klitschko, and John Ruiz.

His professional record ended with 23 wins, 24 losses and one draw.

But he insisted that none of them hit him anywhere near as hard as Iron Mike.

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Julius Francis throws a punch at Audley Harrison

He told the Daily Mail in 2020: "I hit him with some of my best shots and my best shots were not good enough, even if I did draw blood.

"But Tyson had great head movement and great foot movement. He would hit me on one side of my body, then the other, and when I tried to hit back, he was not there.

"His foot movement was ridiculous. I thought I was a good fighter, and to a point I was, but when you get to meet someone like Mike Tyson, they are on a different level.'

"Towards the end of the fight there was one upper cut that lifted me off the floor. That sticks in my memory.

"I have sparred with Frank Bruno, Lennox Lewis and fought Vitali Klitschko but Tyson's power is different. He not only has the power, he has the movement.

"The hardest single punch I faced was actually from Frank Bruno but Tyson hits just as hard but he will land three punches in a short space of time in the same area.

"During the fight Tyson did not actually get me with that many head shots, it was actually the body shots that did the damage.

"Some people in boxing say that they would not have fought Mike Tyson but I would have been a fool to turn down the chance.

"If I had landed that one punch, he had gone over and I had beaten Mike Tyson, my name would have been made forever. I have no regrets.

"I would have just changed one thing: the outcome!"

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