The Unbeatable Was Beaten (1970)

Nikos Firfiris will respond to the radio appeal and donate blood to Julia Papamarkou. Despite her wealthy father's insistence, Nikos will refuse to take money, but his partner in the grocery store will ask for it on his behalf. Nikos will accept the invitation to the party organized by Julia. Her fiancé, Jim, seeing Julia's obvious affection for Nikos, sets a trap for him with the help of his accountant, Zisis, and Nikos ends up in prison. Jim is now certain that he will marry Julia so that he can save his father's business from bankruptcy...