Tonga's 30-12 victory over England in Perth on Saturday began with a first for Haumole Olakau'atu: leading the Sipi Tau at the World Cup.
Co-captains Jason Taumalolo and Addin Fonua-Blake told him to lead the traditional war dance on day two of the team's pre-tournament camp.
The Manly forward had never performed it before and practised to learn the words.
"I was just trying to remember the words as I was saying the Sipi Tau," Olakau'atu told AAP.
"It's a lot of emotions going through your mind, and just the adrenalin rushing through your body ... but it was more so just trying not to forget the words and taking my time."
He said the selection was a privilege and a proud moment for his family, particularly his parents.
Olakau'atu was overcome with emotion singing Tonga's national anthem, then again after playing all 80 minutes and scoring twice.
The nine-capped Tongan said the anthem moved him because he was playing for his family, country and faith.
After recent strong seasons at Manly and three State of Origin appearances from the bench for New South Wales, he was grateful to play a full match for Tonga in his preferred position.
"Just a lot of gratitude towards the coaching staff and Woolfey (coach Kristian Woolf) for believing in me and trusting me to fulfil that position and play the full 80," Olakau'atu said.
He plans to lead the Sipi Tau again against Lebanon on Friday, hoping to bring more enthusiasm and emotion.
"I got a lot of positive feedback from the boys in the squad, so as long as they're happy, that's all that matters."