Obviously this is more of a career achievement than for a single fight … even guys not known for their stamina could get fit for one particular outing. Here’s mine, subject to revision after you fine folk weigh in and enlighten me: Heavyweight: Rocky Marciano Cruiserweight: Evander Holyfield Light heavyweight: Matthew Saad Muhammad Super middleweight: Roy Jones Jr Middleweight: Marvin Hagler Junior middleweight: Mike McCallum Welterweight: Ray Robinson Junior welterweight: Duilio Loi Lightweight: Henry Armstrong Junior lightweight: Brian Mitchell Featherweight: Troy Dorsey Junior featherweight: Wilfredo Gomez Bantamweight: Jeff Fenech Super flyweight: Johnny Tapia Flyweight: Yuri Arbachakov (I admit I am less well-schooled on the lighter end of the weight spectrum so someone will likely have far stronger picks than me. I also went with Wilfredo Gomez even thought he had a lot of shorter fights because of his KO percentage and because he often looked tired … but even so he always picked it up late and finished strong despite looking weight-drained or depleted.)
For Super Bantamweight / Junior Featherweight I would say Daniel Zaragoza. Man was a machine who just didn't stop. I'd highly recommend his bouts against Hatanaka, Tatsuyoshi and of course his ATG trilogy against Banke.
Just to add an extra weight class onto this list - at Light Flyweight I'd go for Jung Koo Chang. He was a non-stop machine for the full 12 rounds. Highly recommend checking out his fights if you've not got round to it yet.
I'm not sure I ever saw Sanchez tired at featherweight. Same thing w Monzon at middleweight but I could be wrong there ... Hagler was in insane shape but I feel he kind of doubted his own stamina against Vito, Duran and Leonard .. I think he kinda almost punched himself out in the first Obel fight but have to revisit it .. Leonard was insanely conditioned at 147.
I have a hard time arguing emphatically against any of these... The one I had chambered was... TROY DORSEY but you already listed him. Other than that Khaosai Galaxy at SuperFly deserves a mention. He was a machine. I'll throw a wild card in the welterweight and say Crisanto Espana.
In fact I think Al Heyman stole Benn’s conditioning routine for Mayweather Jr. He was that impressed when out in Spain with him when he was involved with Bruno
Heavyweight: Rocky Marciano Cruiserweight: Vasilly Jirov Light Heavyweight: Saad Muhammad Super Middleweight: Joe Calzaghe Middleweight: Marvin Hagler Junior Middleweight: idk, 154 kinda sucks Welterweight: Ray Leonard Junior Welterweight: Aaron Pryor Lightweight: Henry Armstrong Junior Lightweight: Floyd Mayweather Jr. Featherweight: Troy Dorsey Super Bantamweight: Jeff Fenech Bantamweight: Fighting Harada Super Flyweight: Sung-Kil Moon Flyweight: Yuri Arbachakov Light Flyweight: Myung Woo Yuh Minimumweight: Baby Jake Matlata