Any Which Way You Can (1980)

Just as underground bare-knuckle fighter Philo Beddoe (Clint Eastwood) is about to retire, he is asked by the Mafia to fight East Coast champion Jack Wilson (William Smith), who has been crippling opponents in his victories. To get Philo to agree to fight, the Mafia kidnaps his old love, Lynn Halsey-Taylor (Sondra Locke). When Jack finds out, he agrees to help Philo rescue Lynn. Afterward, Philo and Jack decide to fight anyway to settle who is the better brawler.