DEONTAY WILDER was hailed in defeat for a chin as tough as his fighting spirit after Tyson Fury's trilogy triumph.
But fellow heavyweight Dillian Whyte claimed he once saw the American knocked out cold and 'twitching' by legend Wladimir Klitschko during sparring.
Dillian Whyte was a sparring partner of Wladimir Klistchko in 2014
Title hopeful Whyte was a sparring partner for former world king Klistchko in 2014.
The Brit revealed that other training partners - including Wilder- took a beating left, right and centre.
Whyte told Sky Sports: "I've seen him getting knocked out, Wladimir knocked him out.
"He knew what happened. He had his hands up. He was roughing Wlad up, bringing the smoke, and he was going wild.
"Wlad backs up, changes his footwork, feinting, feinting, jabs to the body, throws that feint jab, left hook. Wilder had his hands up, he was gone.
"It wasn't no knockdown, he was knocked cold. Properly twitching as well.
"That's why they probably didn't want him to fight Wlad, because Wlad was going to fight him as a pro and Wilder never fancied it the whole time."
Whyte admitted after watching sparring partners get put down he went hell for leather with Klitschko - resulting in him being sent home from the camp.
But he would return, and be joined by rival Anthony Joshua, who Whyte beat in the amateurs in 2009 before losing the rematch in the pro ranks six years later.
The two Londoners clashed in Klitschko’s camp, with the pair being split up before a fight outside the ropes broke out.
Whyte explained: "I wanted to punch Joshua up, at first, because he was talking a lot of smack.
"There was genuine annoyance there. Bashir [Ali] and a couple of guys stopped me getting at him and then it sort of got squashed. It was a bit edgy."