In 1953, Stanley Kubrick took $3900 of his savings to finance his first film, "The Day of the Fight". It's a short documentary about middleweight boxer Walter Cartier for whom Kubrick had already documented for Look in a photo assignment titled "Prizefighter Walter Cartier". He later sold the film to RKO pictures for a profit of $100.
RKO added 4 minutes and 15 seconds of general boxing footage and narration as well as differing credits and music.
This version of the film has now appeared online and can be seen and downloaded HERE at the website of Mutiny Company. Somewhat mysteriously, it says on the site that an unmarked DVD-r from an anonymous source provided the film.
Mutiny Company - The Day of the Fight
Day of the Fight - Wiki
Stanley Kubrick Wiki
Warner Brothers - Kubrick Site
Stanley Kubrick - Senses of Cinema