His professional career started when he placed third in his first ever event at just 15 years old. With an impressive background in swimming, speed skating, duathlon, aquathlon, triathlon and cycling, winning national championships in all six sports, he was a well-rounded athlete.Stewart made his first World Championship team in 1989, aged 18, and finished in an incredible fourth place. At age 20, Stewart experienced one of the defining moments of his career, winning the illustrious World Championship in his hometown, the Gold Coast. He remains the youngest triathlete ever to be World Champion.Following this famous victory, Stewart went on to win the World Indoor Championship, a World Cup Championship, 10 ITU World Cup wins, the 1996 and 2000 Australian Championships and, in the process, added two World Records to his name. Stewart is in the Guinness Book of World Records for the fastest triathlon time in the world.