In 1914 he won New South Wales' State amateur heavyweight boxing championship and in 1915, he turned professional in boxing signing to appear for the promoter Snowy Baker. That year he promptly claimed the national championship. In his final professional bout in 1916 he was knocked out by Les Darcy. Earlier in that bout Hardwick broke both of Darcy's front teeth, and the hurried dental correction done after the fight (re-pinning the teeth on gold posts) ultimately resulted in complications and an infection that caused Darcy's death in 1917.