Gould met then 20-year-old amateur boxer James Braddock at Joe Jeanette's gym in Hoboken, New Jersey in 1925. With Gould as his manager, Braddock turned pro in 1926 and went 14-0-2 before losing his first fight. After a completely one-sided loss to defending Light Heavyweight champion Tommy Loughran in July 1929, Braddock's career fell into decline as he lost more than won. By 1933, unable to support his family as a boxer, Braddock worked as a longshoreman and went on public assistance.
Gould was instrumental in forging a phenomenal comeback for Braddock in June 1934 when Primo Carnera was scheduled to defend his Heavyweight title against Max Baer. The promoters needed an opponent for up and coming John “Corn” Griffin on the undercard. Gould pleaded for Braddock to be inserted as Griffin's opponent stating that Braddock needed money just to put food on the table for his children. They agreed to pay him $250 for a 6-rounder against Griffin which Braddock won in 3 rounds. Five months later Braddock decisively won a rematch against John Henry Lewis in 10 rounds followed by an easy 15-round decision against Art Lasky.
Braddock was then slated to face Max Baer, the reigning Heavyweight Champion of the world. On June 13, 1935 at Madison Square Garden, the 10-to-1 underdog Braddock won the World Heavyweight Championship in one of the most stunning upsets in boxing history. On June 27, 1937, Braddock lost the title to Heavyweight contender Joe Louis. Seven months later, in the final fight of his career, he defeated Tommy Farr in Madison Square Garden.