Balboa was a fictional character, so this question is not realistic. Now if you meant Rocky Marciano vs Tyson I would say the Rock would KO Mike Tyson by the 7th.
I'd choose Mike Tyson, I think his Defence and Power is better than Rocky Balboa.
If it happens in a movie, Rocky would win. If it happens in real life, Tyson.
Actually, a lot of the sparring in the Rocky films looked pretty realistic.
rocky would take everything tyson threw at him, and score a come from behind ko in round 11.
Who would win? Depends what Stallone writes in the script!
Really? smh