Tyson Fury will face former UFC champion Francis Ngannou in a fight under official professional boxing rules in Riyadh, Saudi Arabia, on October 28.
The clash, which is billed to decide the "Baddest Man on the Planet", will have three judges ringside adopting the 10-point must system - but both fighters are promising to win by knockout in devastating fashion.
Fury is making his return to the ring following last December's dominant 10th-round victory over Derek Chisora, which was a third defence of his WBC world title.
He said: "As soon as that bell goes, it'll be bombs away! This guy is supposed to be the hardest puncher in the world, but let's see how he reacts when he gets hit by the Big GK.
"I can't wait to get back out there under the lights. I'm looking forward to showing the world that The Gypsy King is the greatest fighter of his generation in an epic battle with another master of his craft.
"Francis looked tough when he jumped in the ring after the Whyte fight, but there is no one tougher than me, and you'll all see that in devastating fashion on October 28.
"I'd like to thank my promoters Frank Warren and Bob Arum, my manager Spencer Brown and the guys at Riyadh Season for making this incredible event possible. It's going to be a fight for the ages. Get up!"
Ngannou said: "I've been waiting to meet Tyson in the ring for the past three years. My dream was always to box, and to box the best.
"After becoming the undisputed MMA heavyweight champion, this is my opportunity to make that dream come true and cement my position as the baddest man on the planet.
"I'd like to thank Riyadh Season and my team at 3Point0 Labs for helping put this event together. All I will say to Tyson for now is he better dance in that ring because if I touch him, he's going to sleep".
