On Saturday night, WBC heavyweight champion Deontay Wilder threw down the gauntlet to Anthony Joshua after devastating Bermane Stiverne in a mandatory defence of his title.

After knocking his opponent out in a brutal first round at the Barclays Center in Brooklyn, Wilder called out to his British rival: "I declare war on you. Do you accept my challenge?"

There appeared to be no contest between Wilder, who is unbeaten in his professional career, and Stiverne, who was sent crashing to the canvas three times before the referee called time on Saturday's fight in the first round.

His sixth title defence, Wilder now has 39 undefeated fights and 38 KOs to his name and wants to unite the heavyweight titles.

Asked by Showtime Sports about fighting IBF, IBO and WBA champion Joshua, 28, he said: "I've been waiting on that fight for a long time now. I declare war upon you. Do you accept my challenge? I've been waiting for a long time. I know I'm the champion. I know I'm the best. Are you up for the test?

"A king doesn't chase the peasants. A king takes kings. I want Joshua. If he doesn't give me the fight we have other plans. The world wants Joshua, the world wants Wilder, I want Joshua. Joshua come and see me baby. No more dodging, no more excuses. Make the date, don't wait."

Matchroom's Eddie Hearn, who promotes Joshua, was in contact with his fighter with respect to Wilder.

Both Hearn and Joshua believe the size difference, in terms of weight, is very wide - and Joshua believes it will be too wide for Wilder to win.

Joshua weighed in at 254-pounds for last Saturday's fight with Carlos Takam. Wilder was only 220 for Stiverne. Both champions are pure muscle and have very little fat.

 "I was really interested to see the weight of Deontay Wilder on the scales, [220-pounds]. I texted that to Anthony today, Deontay Wilder, [220-pounds]. I shouldn't really tell you the reply, but it was 'I'll eat him,' and the size difference is huge. It's two-and-a-half stone now between those two [35-pounds]," Hearn revealed to Sky Sports.

"Of course Joshua has told me we want all the belts and that means taking on all the champions. The gentleman over there sitting ringside, Tyson Fury, he's in the plans for 2018 as well. Joseph Parker as well. I had a text from his promoter tonight, asking if we fancy making that fight next. Everybody wants to fight Anthony Joshua and you will see him fight everybody."