Coming from Perth, Western Australia, Matkovich became a scholarship holder at the Australian Institute of Sport in 2000. He had previously been a member of Australia's water polo team. He made his international debut in 2001 at the 2001 World Championships in Fukuoka, Japan where he collected a gold medal by swimming in the heats of the 4×200-metre freestyle relay. Australia proceeded to break its own world record in the final.