The Boxer (1972)

After winning a fight he was threatened to lose, boxer Teddy Wilcox finds his manager murdered and becomes the prime suspect. Escaping the police, Teddy goes on the run through a dangerous underworld to uncover the truth. He must confront a web of conspiracy and betrayal, orchestrated by someone he thought he could trust, to find the real killer and prove his innocence before it is too late. Aka Un uomo dalla pelle dura.