Foreman would stop him. Vitali was tough, maybe he could stay on his feet, getting pummelled on the ropes like an elongated Chuvalo. Or maybe Foreman rips his face off.
Isn't Vitali being written off a.bit too easily here? Foreman of that period was a monster yes, but flawed. He had never been in a really tough fight in his life yet, and was overconfident. It cost him his title against Ali. Now, Vitali has flaws too, but his strengths do offset some of Foreman's. For one, he was in excellent condition and very durable. His ability to absorb a big bomb was great. And he was generally hard to hit. Only Lennox had any real success tagging Vitali regularly. So despite George's vicious power, I don't see Vitali folding like Frazier did, who was made to order stylistically for George. Secondly, George was always the bigger man but here, he is outranged and outsized by Vitali. I can't see Foreman being able to push and bully Vitali around like he did Joe. George was not hard to hit. Ali hit him nearly at will sometimes, and while Ali was quicker than Vitali, Vitali also liked to throw straight, thudding punches. Added to a superior reach and superior power to Ali, and from range Vitali has to be a threat to George, who waded in almost without care against Ali. Doing the same against Vitali would be inviting trouble. Yes, Vitali held his hands low, but he was very mobile for a big fella and leaned back a lot from shots. Not easy to hit. He would often counter punch in this fashion. I think George plodding forward would be on the receving end of many stiff counters as so many of Vitali's opponents were. So for me, this fight is by no means a given. George was a beast, but a heavily flawed one. Vitali was skilled, tough, durable, huge and very well conditioned. Not an easy opponent.
I too am picking Foreman but l don't think it would be a walk over. l think it would go 7-8 rounds. One think l noticed on the Lewis fight was that by the 6th round Lewis was walking him down and my guess is that he felt he could do that because Vitali's power had diminished a fair amount since the 2nd round. But if George ever got him on the ropes the way he did Ali he'd probably stop him with a body punch. Those were vicious punches Ali took to win that fight.