Jack Britton and Ted Kid lewis Erik Morales and Marco Antonio Barrera Obviously guys like Ali and Frazier, Robinson and LaMotta, Pacquiao and Marquez etc had great rivalries with each other, but I don't feel as if they depended upon their rivals as much as the aforementioned did to seal their greatness (aside from Marquez, but that was one sided, Pacquaio didn't need him near as much as Marquez did him).
Frazier too, one sided. He clearly he had an excellent career aside from Ali, as did Marquez aside from Pacquaio, but their wins in these respective fights really cemented their ATG status.
Dempsey-Tunney Tunney-Greb Louis-Schmeling Petrolle-McLarnin Petrolle-Canzoneri Charles-Moore Burley-Moore Canzoneri-McLarnin Langford-Jeannette Langford-McVey Leonard-Tendler Conn-Louis
Jack Dempsey - Luis Firpo. That fight transformed Jack Dempsey from Champion to Legend! Joe Louis - Max Schmeling. Those two fights did the same for Joe Louis, especially the second one. Jersey Joe Walcott - Ezzard Charles. Four fights. Rocky Marciano - Ezzard Charles. Two fights. Floyd Patterson - Ingemar Johanson. Three fights. Muhammad Ali - Joe Frazier. Three fights. Tyson Fury - Deontay Wilder. Three fights.
Duran brought out another level of greatness for Ray Leonard in Montreal. Sure, we can speculate (I do) that Ray’s strategy perhaps wasn’t the wisest but I wouldn’t trade those scintillating periods of Ray fighting off the ropes with those laser fast hands, mano o mano, for anything. What a fight that was - in just the one match, Ray moved from a ridiculously talented baby faced assassin to an uber tough hombre, driven to win and take whatever licks necessary along the way. Similar to Ali’s moment of reckoning in the same regard when he faced Joe Frazier in The FOTC.
Duran brought out the best in Ray Leonard. Leonard brought out the quitter in Duran. The third dance was without music.