The former UFC lightweight champion was speaking at an event in his home country of Dagestan back in 2017, when the fan came over to him.
The man, who was wearing a black T-shirt and a matching pair of jeans, asked Nurmagomedov if he would mind testing his strength against him in the form of a body shot to the midriff – with The Eagle evidently finding the whole thing rather amusing.
Needless to say, he was only too happy to oblige.
Fans were left stunned when he unleashed a right hand at the fan without warning, who bravely tried to firm it before eventually dropping to his knees.
The pair did share a hug at the end of the clip but there’s no doubt he must have been in a world of pain.
It is unclear if the incident was staged.
WATCH: A fan once asked Khabib Nurmagomedov to punch him in the stomach and instantly regretted it
Check out the video below…
Nurmagomedov went on to win a unanimous decision against the hard-hitting Barboza a few months later. The win also earned him his first Performance of the Night bonus.
Of the Brazilian, Nurmagomedov said after the fight: “In the beginning of the fight, all my training camp I thought about his kicking, his knees, and for me it was very interesting to feel everything what people talk about him, his striking game, you know.
“When the fight began, of course I knew he was going to worry about my takedowns too. All training camp we planned to pressure this guy, make him tired, make him work. He kicked me a couple of times when the fight began but I don’t feel nothing.
“When I took him down, his coaches were very close, and I just talked with them, like tell him get up, stuff like this. I don’t remember everything but I talked with them too. I just talked with him too with his coaches with his corner because when I go to the cage I enjoy my fight with my opponent with what I do.
“This is really important because this is not just about hard training or stuff like this, this game involves mental [warfare], and this gave me good energy.
“I don’t know if I broke him but I was breaking him, this was the plan, and I stayed focused. When the third round began, I understood this was my fight, you know. It was a great performance from myself.
“It was very hard training camp because I come back after injury, I come back after surgery on my leg, you know. It was a little bit hard training camp but when I finished my training camp the last couple of weeks before my fight I felt great. I understood my shape is very good, my weight is good, you know, I was very hungry to come back.
“When I fought Barboza, I didn’t think about a title shot. I just thought this guy is very tough and I have to come back, beat this guy, then we’ll see what’s next. I just focused on my opponent.”