Ramirez by KO late in a war. Too tough, and outside of Ruben Olivares stopping him when he was a kid, Ramirez was never stopped (the Chavez fight was an accidental headbutt) in 112 fights against a lot of tough fighters and he got off the deck against a better fighter than Chico in Rosario and knocked him out. I think Ramirez is still strong in the late rounds and takes Chico out of there.
Ramirez bombs Corrales out somewhere in the middle of the fight. I don't see how Diego could actually be favoured by anyone. He COULD win the fight...but all things point to Ramirez in a war. Tougher, more experienced against a better quality of fighter AND performed better in those tests than did Corrales. Ramirez southpaw jab would fuck Diego's face up.
I'd favor Ramirez by KO. Corrales would have no defense against his left hand, and Ramirez was likely tough enough to take whatever Corrales would dish out (whereas the same can't be said of Corrales and what Ramirez dishes out).