Walton competed in the triathlon at the 2000 Summer Olympics. He took twenty-seventh place with a total time of 1:50:57.66. Walton was a powerful swimmer and strong cyclist. He typically established a large lead coming into the run leg but was frequently caught by faster runners before the finish. He enjoyed significantly more success in non-drafting events such as Noosa triathlon, which he won 7 times and holds the course record. Walton coached his longtime partner, Emma Snowsill and Emma Moffatt.