Prime Rahman fought prime Corrie Sanders and could take his punches and Peter is slower than Sanders. I'd say Rahman wins by UD12 or KO.
Rahman wins it IMO. Peter's only real advantage here is his chin. Rahman has the advantage in the jab department, had a better straight right hand, superior fundamentals, and managed to go 10 and 12 rounds with Tua and beat Corrie Sanders, both of whom were bigger punchers than Peter was. I like Hasim to outbox him and land the more meaningful and eye-catching power shots. Peter would be dangerous, though.
Rahman takes this with little trouble. Peter sucks and always has. Rahman was a decent fighter at one time. Even Peter at his best vs a completely shot Rahman would be a close fight.
Rock on the outbox, plus gotta remember Peter had very overrated power, never really stopped elite level except Maskaev and we all know Maskaev as well as Rock dont got no chins!
Prime Rahman could stick that jab out like a baws. He wins an easy decision. Rahman was putting a clinic on a beast in Tua. Peter was super slow compared to that Tua.