On August 2, 1980, hometown boxing hero Tommy “Hitman” Hearns won the WBA welterweight title, knocking out Pipino Cuevas in the second round of their bout at Joe Louis Arena. Hearns trained at the renowned Kronk Gym in Detroit.
Click the link for video of the entire fight, with the knockout at about 5:45. What a punch.
Source : Detroit Historical Society Facebook Page.