[5] Petaia made his Super Rugby debut on 7 April 2018, round 8, against the Brumbies at GIO Stadium, Canberra.

[6][7][8] Petaia scored his first ever try in the Super Rugby and for the Queensland Reds in round 14 against the Hurricanes, losing narrowly, 38–34 in Wellington.

[11] Petaia was called up to the Australia squad by coach Michael Cheika in early August 2018, before Bledisloe Test One in Sydney, New South Wales.

[13] Petaia's international debut was during a pool match against Uruguay in the 2019 Rugby World Cup, scoring a try on his second touch.

[16] On 9 December 2024, he was selected for the National Football League's International Player Pathway (IPP) program at the position of tight end.