Pearce entered a U-16 handicap race at the age of six, managing to finish second. Pearce left school early to become a carpenter, and then worked in the fishing industry with his father. He joined the
Australian Army in 1923, and attained the rank of
Staff Sergeant. In 1926, after winning the Army heavyweight boxing championship, he left the army to become a full-time rower. He was a competitor for the
Sydney Rowing Club. Standing at 188 cm and 95 kg, Pearce entered the amateur national sculling championships in 1927, which he won and retained in 1928 and 1929. This gained him selection for the Olympics in 1928, where he was the only rower selected. At the games, he carried the Australian flag at the opening ceremony. Pearce won all of his races with relative ease. He defeated his first opponent
Walter Flinsch of Germany by 12 lengths and his second opponent Danish rower Schwartz by 8 lengths. In the quarter-final he was easily beating French opponent Saurin when a family of ducks strayed into his lane. Pearce momentarily stopped rowing to let the ducks pass; he still won with the fastest time of all 8 competitors in that round. In the semifinals, Pearce was pressed by
David Collett of Great Britain, winning by three-quarters of a length (roughly 1.5 seconds). In the finals he became the first Australian to win gold in the single sculls by defeating
Kenneth Myers of the United States by 9.8 seconds. In winning he established a new Olympic record, some 25 seconds faster than the previous mark. This also earned him the
Philadelphia Gold Cup, which represented the amateur champion of the world. He was awarded an Honorary Life Membership of the
Sydney Rowing Club. In preparation for the 1928 Olympics, Pearce attempted to enter the
Diamond Sculls at the
Henley Royal Regatta, but was barred as he was a carpenter by trade: the rule relating to
amateur status then in force barred anyone "Who is or has been by trade or employment for wages a mechanic, artisan or labourer." This socially discriminatory wording was deleted in 1937. Pearce was unemployed during the
Great Depression, only entering the
1930 British Empire Games in
Hamilton, Ontario, through the charity of friends. He won the single sculls at the Empire Games and attracted the attention of whisky magnate Lord Dewar, who offered Pearce a job in Hamilton as a salesman. This made Pearce eligible to compete in the Diamond Sculls at the Henley regatta and he entered again in 1931. In the first round at Henley he was against Tom Brocklebank, who had served as stroke of
Cambridge University Boat Club in the
Boat Race. Pearce had a weight advantage of three and a half stone (22 kg) over Brocklebank and was a clear favourite. Having taken an early lead Pearce was content to scull a couple of lengths in front until halfway along the enclosures (in the last 500m of the course) where Brocklebank pushed hard and came back level. Pearce countered, but only just in time. C. T. Steward commented in the Henley Records that 'Pearce won comfortably by half a length'. However,
Dickie Burnell, who watched the race as a schoolboy from the Stewards' box on the finish line, wrote that Pearce looked anything but comfortable in the last few strokes. Pearce had no such trouble in later rounds and won the final against F. Bradley of
Pembroke College, Cambridge, by six lengths. Pearce defended his Olympic title in 1932, this time winning by 1.1 seconds over American
William Miller. The remainder of the field trailed by nearly 30 seconds. Although he was a Canadian resident, Olympic rules required that he represent Australia. ==World champion professional==