Peter was more physically strong than a massive puncher. He could crack with clubbing shots, but he never even dropped Maskaev, for instance (although he was past his peak there). Norton probably beats up/outclasses a tired, sloppy Peter in the later rounds after surviving a couple shaky moments.
Norton was the better all around fighter but Peter’s strength, power and bullish style might force Ken to fight off the back foot where he doesn’t want to be. And while Sam’s chin could certainly be cracked I think it was solid enough to withstand anything Norton could throw at him. I love Ken Norton and again rank him much higher but the chemistry is just bad for him here.
This, Norton is a level above Peter. I mean after all were talking about Peter a guy who went 24 rounds with an obese middle weight and never came close to stopping him and arguably lost one of those fights . I mean he lost to Robert Helenius , he ain't beating a prime Norton. I'm not sure Peter beats a prime Quarry.