Every Which Way But Loose (1978)

This unusual combination of bare knuckle fighting and lighthearted romp was also a comedic change of pace for its rugged star Clint Eastwood. Eastwood plays trucker Philo Beddoe, a revered brawler who lives in a shack with his best pal's feisty, elderly mother (Ruth Gordon) and an orangutan, Clyde, who sips beer and thumbs his nose at authority. Philo is preparing for a bout against the wishes of his mother and his new love interest (Sandra Locke). If clashing with the women in his life weren't enough, he has to deal with his cocky opponent, gamblers, and a chopper gang who constantly harrass him. Fortunately, he does have Clyde backing him up as well as his trusty companion Orville Boggs (regular Eastwood collaborator Geoffrey Lewis).
This bizarre hick comedy was a surprise hit and spawned a sequel featuring many in the original cast. The country soundtrack combines the talents of Steve Dorff and Snuff Garrett and boasts a hit single by Eddie Rabbit.