This would have been a close fight but I favor Rocky due to styles.
Rocky has a pretty record mostly made of old men, and he doesn't have many title defenses as undisputed. Most boxing fans know this but few have sat down to watch his fights or study his era.
Rocky was like a slightly shorter version of Joe Frazier but with more power in the left hand and he is probably the only other heavyweight with a better stamina than Joe Frazier.
Prime vs prime I see it playing out like Frazier-Ali but Rocky had more in the tank for later rounds. Lighter men, and lighter punchers, put Ali on his ***, I don't see why Rocky couldn't.
Personally I think the Rock took PEDs because at less than 190lbs he kayod much bigger men by outworking them, watch how Rocky ended his first bout with Charles, round 15 that was not normal IMO he was on something and Ali had many defensive flaws I see Rocky outworking Ali late fight.
Marciano would have murdered Ali. Ali got hit by many fighters and was dropped too. Marciano hit's Ali and it's a TKO stoppage by 10.
Boxer beats puncher. Ali wins.
Ali by a tough decision.
https://en.wikipedia.org/wiki/The_Super_...
Sweet Science Aficionados,
Disregard eras with EACH fighter in his PRIME.
Q 1. Who wins a 15 round heavyweight bout:
Rocco Francis Marchegiano aka Rocky Marciano
VS
Muhammad Ali
Tape:
Marciano: 5 ft 11 in & 68 inch reach
Ali: 6 ft 3 in & 78 inch reach
source: curiosity