Was Povetkin’s uppercut really powerful or was it Whyte’s chin?

[Toffee]

Completely different circumstance to the one Joshua knocked him out with.

And completely different punch to the one Povetkin hit Joshua with. Joshua saw it, it came from further away and from directly in front if him.

Povetkin's punch was from in close, from down low, on an angle that ripped his head around on his neck.

You can question why Dillian got himself in a position to be hit with it, but I don't think a punch like that raises serious questions about his chin.