Wilder is now the reigning WBC heavyweight champion, and he mentioned that he is willing to put his belt on the line just for a chance to fight Joshua as he believes it would be "the biggest mega-fight in world history".
Klitschko nailed Joshua with hard shots by the ropes and in the following rounds continued to get the better of Joshua, who was going past the 7th for the first time and appeared gassed.
Klitschko, who held at least one version of the title for 15 years from 2000, took mandatory eight counts both times but was then backed into a corner and forced the referee to step in to protect him because he was unable to defend himself.
Hearn said: "In terms of worldwide stardom, I said "you win this fight and you become the biggest star in British sport and the biggest star in world boxing".
The current champions are Joseph Parker, Deontay Wilder and Anthony Joshua but a certain Tyson Fury from the United Kingdom is also lurking upon speculation of a summer comeback.
In Tyson's own words, one fighter has seemingly altered what was a bleak landscape for boxing. They won't pay for it, they want the best and the best is Joshua.
By the end of the round, Kltschko had Joshua in trouble after landing a powerful left hook that rocked him, and in the following round he dropped Joshua with a crushing right hand.
Once dubbed the "Baddest Man on the Planet", Tyson reignited the heavyweight division in the 1980s with a ferocious 37-fight win streak.
"I was a shadow of my former glory but now I'm on my way back".
Tyson believes that while there are a lot of good boxers, and a lot of good fights, an entertaining heavyweight is what boxing needs.
"I like that he's patient, too, he's like Frank Bruno but on steroids (sic)".
I was talking to him and I told him, "If you let me get through this round, I'm going fuck you up". WBC and WBO World Champions - Deontay Wilder and Joseph Parker - have also expressed interest in the fight.
"Unbelievable fight, a great fight for a heavyweight clash".
"It didn't slip away - I just couldn't be bothered no more".
Speaking to the 'BritishBoxers' website, Fury said he's putting plans in place for his comeback, and said he wants to fit in a few bouts against other opponents before hopefully facing Joshua next April.
"Of course we have a rematch in the contract. I've never seen an entrance quite like his before with the flaming "A" and "J", he adds.