Joshua and Povetkin met for the first time since the announcement of their fight, which will take place on September 22 at Wembley Stadium.
The Brit has been forced by the WBA to defend his heavyweight belt against the man who brutally knocked out David Price last time out.
But fans of Wilder voiced their discontent at the DAZN launch in New York after talks between the American and Joshua broke down.
And Hearn quickly shot them down by aiming a quick-witted dig at the WBC belt holder.
“There’s more people here than there were at Deontay Wilder’s last fight” Hearn quipped.
The DAZN launch was also shrewd in further controversy as Jarrell ‘Big Baby’ Miller stormed the stage during Joshua’s face-off with Povetkin.
Meanwhile, Joshua has previously said he is looking forward to making his boxing return against Povetkin.
“I can’t wait to get back in the ring. The end of March feels a long time ago now,” he said.
“Povetkin is a serious challenge that I will prepare meticulously for.
“He has serious pedigree and only a fool would underestimate what he brings to the table.
“Training hasn’t stopped for me, but the next 10 weeks ahead will be intense both mentally and physically.
“I will push myself to breaking point to make sure I am in peak condition for another huge night for British boxing at Wembley Stadium on September 22nd.”
Source : EXPRESS