Each opponent has a weak point. Learn about it. This will help you to beat the hell out of them...
 
 

Minor Circuit	World Circuit
Glass Joe	Piston Honda 2
Von Kaiser	Soda Popinski
Piston Honda 1	Bald Bull 2
Major Circuit	Don Flamenco 2
Don Flamenco 1	Mr. Sandman
King Hippo	Super Macho Man
Great Tiger	The Dream Fight
Bald Bull 1	Mr. Dream
	Mike Tyson