The Square Jungle (1955)

Grocery clerk Eddie Quaid, in danger of losing his father to alcoholism and his girl Julie through lack of career prospects, goes into boxing. His cop friend McBride finances him; ex-con Bernie Browne trains him. Three years later, he is a challenger for the championship, and Julie re-enters his life. Can she win him back from a predatory blonde? And why does the prospect of Eddie's winning worry Bernie more than his losing?