"My natural character is usually quiet and humble but at that moment I was over the moon," the elated champ said.
Heta-Morris won a title at the same competition last year, but this year's tournament saw arm wrestlers entered from Malaysia and Singapore, giving it an Oceania status.
Heta-Morris has been arm wrestling for only about two and a half years and started a new training regime six months ago.
He said he was nervous to see if it had worked, heading into the big competition last weekend.
"I think I didn't feel as confident because I have a different training process now," he said. "But when I got over there I was told I was the one to [beat] and I beat someone who beat me last year, which felt great."
Heta-Morris thanked his main sponsor, Rotorua business Insurance Towers, for helping him get to Melbourne.
He is now working towards the 2014 World Arm Wrestling Championships in Lithuania in September, training four times a week at the gym and at home.
Heta-Morris and another Kiwi made history last year as the first New Zealanders to compete at the world champs.
Heta-Morris finished 11th in the prestigious 110kg-plus class and gained plenty of experience from the event.