Australia's youngest ever under-19 heavyweight champion is not used to losing.

But Tweed boxing sensation Ethan Hartwig believes the rare loss he suffered at the Oceania Boxing Championships could ultimately be the making of him as a fighter.

The 16-year-old Hart, who won the Australian U19 heavyweight title earlier this year, was representing his country for the first time as he took out a bronze medal at the championships in Samoa last week.

After the tournament, Hart was philosophical about coming away with a bronze medal, telling his Facebook followers he will "be a better boxer” for the experience.

"I gave it 100 per cent but it wasn't to be,” he said.

"A loss like this is hard to take after everyone's support and encouragement, but tonight's result will not define my life or my boxing.

"I'm a better, stronger boxer for the experience... and I'm proud to have had the chance to represent Australia at just 16.”

After the bout Hart thanked his sponsors, coaches and family for their ongoing support.

"I'm extremely thankful and appreciative for those who continue to follow this amazing boxing journey of mine,” Hart said.

"I really can't begin to tell you just how much your support means to me.

"Your encouragement and constant love and support means the world.

"To my coach Chris Carden, I have no words to express my gratitude and appreciation, your patience with me is incredible... I wouldn't be a two-time Aussie champ without your guidance and love.

"To my number one supporters, mum and dad, thank you for continuing to do what you do every single day... I would truly be lost without you both.”

Hart's next test will be his biggest yet: fighting his way onto the 2020 Olympic team.