Thomas '"Hit Man"' and '"the Motor City Cobra"' Hearns began his professional boxing career in Detroit, Michigan under the tutelage of the legendary Emanuel Steward in 1977. Hearns posted a 60-5-1 (46) record, winning seven world championships in six weight classes during his 22 year pro career, beating such notables as Jose 'Pipino' Cuevas, Roberto Duran, Virgil Hill, Michael Olajide, Dennis Bolton, Mark Medal and Wilfredo Benitez. He is known best for his devastating right hand.

Hearns won his first championship by KO'ing the legendary Pipino Cuevas in the second round of their fight in 1980. After defending the WBC welterweight championship successfully three times, he suffered his first career defeat at the hands of Sugar Ray Leonard in 1981.

Despite having a solid career, Hearns was frequently overshadowed from his losses to Sugar Ray Leonard and Marvelous Marvin Hagler, pitting better than stellar performances against both. In his 1981 welterweight unification fight against Leonard, Hearns was ahead on the scorecards before losing by TKO. Four years later, Hearns was pitted against Hagler, he was KO'ed in the third round of a fight many observers called "the greatest three rounds of boxing in history".