Lennox Lewis knocked Mike Tyson out when they finally fought as professionals in 2002.
However, 19 years earlier, the pair shared a boxing ring for the first time in a heated sparring session.
When they were amateurs, both Tyson and Lewis were tipped for future stardom. Lewis won the Junior World Championship representing Canada, but some refused to regard him as the best young prospect around because he hadn't faced Tyson in that tournament.
Iron Mike and his trainer Cus D'Amato preferred not to fly at the time, so he didn't participate in this competition in the Dominican Republic. As a result, Lewis took it upon himself to prove he was the best.
He and his trainer left Canada and drove all the way to spar Tyson at D'Amato's gym in Catskill, New York.
What ensued was a dramatic clash between two future heavyweight icons when they were both just 17/18.
Fans suggest Mike Tyson could be 'in trouble' as new training footage emerges ahead of fight against Jake Paul on 20th July
"I won the World Junior Championships in Santo Domingo, Dominican Republic," Lewis recalled on the Joe Rogan Podcast.
"And I remember the American team were saying, 'Oh, well you never fought the best.'
"I said, 'I thought the Americans sent the best team?'
"They replied, 'Yeah but one guy, he doesn't like taking planes and his manager don't like taking planes either.' They told me it was Mike Tyson and Cus D'Amato.
"So me and my trainer left Canada and we drove all the way up there."
Lewis continued: "First day in the gym, the bell went, he came across and he was trying to kill me.
"I did my Muhammad Ali thing obviously and stayed away from his power, but the first day was really hectic.
"The second day was a little hectic, but got better as it went along, and then the last day I actually got the better of him.
"I remember Cus D'Amato saying, 'Mike! You're gonna meet him some day, don't you do that!'
"And that always echoed on my mind, 'Will we ever fight?' Because Cus D'Amato said we were going to fight, and it did happen."
When they eventually did clash in 2002, after a protracted build-up that forced a change of venue owing to Tyson's behaviour at a press conference, he was past his best and mounted a final challenge for Lewis' heavyweight crown.
The champion at the time was far too good though. Lewis dominated Tyson, KO'd him with a single punch, and retained his world titles.
Now, 40 years on from sparring Lewis, and 22 years on from their fight, Tyson is set to return to the boxing ring to face Jake Paul on July 20.
