This would not be pretty. Ingo's face would look like a stiletto had been taken to it from eating jabs.
Ali sparred Johansson when Johansson was preparing for his 3rd fight with Patterson, Ali only had 4 professional fights at the time but by all accounts he made Johansson look quite bad in their session. So logic tells you a prime Ali would probably stop Johansson between 8-10 rounds in a fairly one sided fight. Here's a brief clip of their sparring session. This content is protected