Inaugural Canberra endurance triathlon champion Ben Allen will use his victory as a stepping stone towards a world title next year.
The Wollongong competitor built up a dominant lead in the swim and bike legs to cross the finish line at Rond Terrace in five hours and 57 minutes on Sunday.
Lisa Marangon was the first female home in 6:40.00 ahead of Canberra's Michelle Wu.
Allen raised his arms in triumph after completing the gruelling course, which consisted of a four kilometre swim, a 120km bike ride and a 30km run.
It was the first time a triathlon had been held over that distance in Australia.
"We don't have enough of these events in Australia and it's a great stepping stone to bigger and better things," Allen said.
"Next year, we have the 70.3 world championships and this would be a good lead-in for that race and for the ITU long distance champs next year.
"You don't get many chances to represent Australia and this is a good stepping stone for me to don the green and gold with the hope of claiming a world title."
It was just the second time Allen had attempted a triathlon over the endurance distance, with his focus on off-road triathlon.
Allen set the pace from the outset and led from start to finish in a dominant display.
"I played catch me if you can and the gap kept getting bigger and bigger," Allen said.
"Each time I saw them they were getting further and further away from me.
"That last 5k's, it stung. All in all, it was an awesome race."
Wu was exhausted when she crossed the line having competed in her first race in seven months after being sidelined with a back injury.
"I was just happy to finish," she said.
"I gave it everything I had on the swim and bike and I was really happy with those two legs because I was only three minutes down on Lisa at the start of the run.
"On the run, I was having really bad stitches from the start and it wouldn't go away, so I knew it would be a very long day out."
T3X Endurance Triathlon: Men: 1. Ben Allen. 2. Rob Skillman. 3. Nuru Somi. Women: 1. Lisa Marangon. 2. Michelle Wu. T3X Canberra Triathlon: Men: 1. Adam Rudgley. 2. Shane Ilgen. 3. James Thorp. Women: Kim Ireland. 2. Angela Ballerini. 3. Jodie Barker.