That was essentially what I was going to comment.

You punch a skull like that, you're breaking knuckles. It happens vs other humans as it is, no way do you punch a gorilla in the face and do even the same amount of damage your hand takes. You're sure as hell not knocking it out.

As entertainment, the idea is awesome, because I can imagine this relatively small guy squaring up against a silverback, all confident and executing the footwork perfectly, throwing a right hook just as hard as he can, and then there's a spray of blood from his hand, followed by the gorilla turning him into steak tartare in a minute or less.

Has dude never been to a zoo that has gorillas? Back in my prime, I would have been a heavyweight, and I feel like a damn twig next to a gorilla, no matter how much height I have on one. And I've never been that close to one. Seeing them twelve feet away was intimidating as hell.