In the late 1970s, four gifted boxers rise up to dominate the sport and define an era: Sugar Ray Leonard, Marvin Hagler, Tommy Hearns and Roberto Duran. Leonard is the all-American feted as ‘the new Ali.’ In contrast, Hagler takes the hard road to the top, and he doesn’t owe the world any favors. Tommy Hearns steps into the ring in Detroit, knocking out most of his opponents in devastating fashion. But it's Roberto Duran whom Leonard sets his sights on to prove he’s more than just a TV personality.