Which fictional boxer defeats Rocky Balboa in their first fight in Rocky III?

Clubber Lang defeats Rocky Balboa in their first fight in Rocky III. Lang is an aggressive challenger who wins the heavyweight title after knocking Rocky out in the third round.

Rocky enters the contest as a celebrated champion who has defended his title repeatedly. Clubber Lang believes Rocky has been protected from the toughest competition and openly challenges him. The fight takes place shortly after Mickey suffers a fatal heart attack, leaving Rocky emotionally unprepared.

After losing, Rocky turns to Apollo Creed for help. Apollo trains him to use greater speed and movement, contrasting with Lang's power and pressure. Rocky then defeats Lang in their rematch and regains the championship.

Mr. T played Clubber Lang, making his film debut in Rocky III. The character is sometimes confused with later opponents such as Ivan Drago, but Lang is specifically Rocky's rival in the third installment and is associated with the phrase “I pity the fool.”