In 1907, embracing the newly popular
Australian crawl stroke, Hardwick won the New South Wales 100-yard championships in 61.6 seconds. In 1909, he came second at the
Australasian Championships in the 100-yard and 880-yard events, behind
Cecil Healy and
Frank Beaurepaire respectively. In 1911, Hardwick won the 220-yard, 440-yard, and 880-yard freestyle at the Australasian Championships. At the 1911
Festival of Empire Games in London, a precursor of the
Commonwealth Games to commemorate the coronation of
George V, Hardwick won both the 110yd freestyle and heavyweight boxing title. He remained in England for the English Swimming Championships, winning the 100-yard, 220-yard and 440-yard freestyle titles. In 1912, he was selected to represent the
Australasia combined team of Australians and New Zealanders at the
1912 Summer Olympics, but could not compete in boxing, as it was omitted for the only time in Olympic history. Hardwick was eliminated in the 100-metre freestyle semifinals. In the 400-metre freestyle, he won his heat and semifinal and held the lead in the final for a period before being defeated by Canada's
George Hodgson and the United Kingdom's
Jack Hatfield, earning a bronze medal. In the 1500-metre, Hardwick won his heat and semifinal and again contested the lead in the final before being worn down by Hodgson and Hatfield. He then combined with Healy,
Leslie Boardman, and
Malcolm Champion to win the 4 × 200 m freestyle relay, splitting 2:31.2 for the fastest leg of the quartet. ==Rugby & boxing==