For as much as a beast he was I don't think he ever got enough credit for how technically sound and smart he was in a ring.
He had a preternatural ability to diagnose opponents, pick up tells and know exactly where the holes were going to be and when they'd be there.
You don't wreck that many people with 6" punches without being in position to know exactly when to uncork them.
I'm doubtful he can generate enough power and speed at this age to put down a kid that size, but the guy is a freak and you never know.
I'm guessing he gets pissed after being peppered for a few rounds and starts viciously headbutting him shortly before it all devolves into chaos.