Hawaii Five-O (1968)

S4E12 Nine, Ten -- You're Dead

A vengeful mob leader targets a retired boxer after the fighter intervenes to protect a young prospect, shattering the novice's hand to save him from a destructive career in the ring. As the mob boss's fury escalates, the boxer must confront his past and navigate the dangerous underworld to safeguard not only his life but also the future of the young fighter he tried to save.