Some of these are dopplegangers, some are in the ballpark. Carl Frampton, Chris Algieri ad Chris Billam-Smith Carlos Monzon and Julio Cesar Chavez Henry Armstrong and Fabio Wardley Harry Greb and Arturo Gatti. Oscar Bonavena and Gilberto Ramirez. Benny Leonard and Joe Calzaghe. Rocky Marciano and Sergey Kovalev. Joe Louis and Michael Hunter. Nino Benvenuti and Liam Smith. Ingemar Johansson and Callum Johnson. George Chuvalo and Ruslan Provodnikov. Emile Griffith and Hassan N'Dam. Kelly Pavlik and Iago Kiladze. Gene Fullmer and Ted Cheeseman. Carmen Basilio and Juergen Braehmer. Nicolino Locche and Erislandy Lara. Tony Canzoneri and Ryan Garcia. Gene Tunney and Dariusz Michalczewski. Fighting Harada and Srisaket Sor Rungvisai. Andre Ward and Droopy Dog.
Beat me to it! First ones that came to my mind and you can really see it when they fought each other.