The Girl from Monterrey

The Girl from Monterrey is a 1943 American film directed by Wallace Fox starring Armida Vendrell as PRCs version of the Mexican Spitfire.

In a Mexican nightclub, some American fight promoters witness Alberto Baby Valdez, the brother of Lita Valdez knock out a champion fighter. At first Lita is angered that her brother has quit his law studies to become a fighter, but the two move to the United States. Lita literally bumps into reigning champion Jerry OLeary with the three becoming inseparable friends. However the American fight promoters force Alberto and Jerry to fight each other or face suspension.

Source: Wikipedia