Davis began boxing at Willie and Charlie Beecher's gym in Brownsville around 1933. At age thirteen, he came under the tutelage of a Jewish trainer, Froike (Frankie) Kane, a former lightweight. At barely fifteen, a year under age, Davis had his first amateur bout under the name Giovanni Pasconi. With his left hook, he knocked out a number of his first opponents and won scores of watches, the only compensation allowed amateur boxers. He pawned or sold most of them to his promoter for cash.