The 27-year-old endured a damaged jaw which he sustained in the second round but fought on bravely in the 12-round contest to win a unanimous decision in a brutal fight in Broadbeach, Gold Coast.
The scores were 116-112, 116-112 and 115-113 in favour of Opetaia in his 22nd fight - all of which he has won, with 17 coming by way of knockout.
Photos and videos uploaded on social media showed an emotional Opetaia with his face covered with blood, hugging his mother and partner.
