Wallace Beery actually got one less vote than Fredric March in the 1931/1932 Academy Awards voting for best actor, but the rules at the time considered anyone with one or two votes less than the leader as being in a tie. So both got Academy Awards.
The film did fine at its first preview until the last reel. As originally written, Champ loses his comeback boxing match, then dies as his son weeps. After going along with the sentimental story until that moment, audiences felt cheated by the downbeat ending. As a result, production chief Irving Thalberg ordered the final scene reshot so that Champ won the match. At the next preview, the audience cheered at the end.
Although the AFI Catalogue specifies the world premiere was in Hollywood (at Grauman's Chinese Theater) on 13 November 1931, the New York Times review of 10 November 1931 says "last night [it] succeeded in stirring the emotions of an audience in the Astor..." Since the review concludes that the film is AT THE ASTOR, it seems likely that it was ready for public viewing immediately. The AFI Catalogue world premiere statement is probably wrong, and that it was just a Hollywood premiere.
Wallace Beery was none too thrilled to be working with Jackie Cooper, sharing most adult actors' distrust of child stars. Cooper would later accuse the star of trying to upstage him and treating him like "an unkempt dog," behaviour he ascribed to jealousy.
King Vidor, feeling that Jackie Cooper "didn't seem to get into the spirit of the part," pretended to fire assistant director Alfred Golden because Cooper was fond of him. After Cooper burst into tears, the article continues, Vidor shot the scene he wanted, then rewarded him for being a good boy by re-hiring Golden. Cooper's autobiography makes no mention of this incident, but notes that as a child Cooper cared neither for Golden or Wallace Beery.
Despite the melodramatic script, King Vidor eagerly took on the film since it emphasized the traditional family values and strong belief in hope-qualities he felt were essential to a good motion picture.