The Twilight Zone - Season 1 Episode 27 -

Even though Jackson breaks his hand prior to the fight, he wins because Henry - a boy who adores the fighter and believes in magic - made the ""big, tall wish."" After the fight the boxer refuses to believe in magic. Henry tells him if he doesn't believe, it won't be true. Jackson just can't believe. Suddenly, Jackson is back in the ring, and counted out.