They slapped their chests and thighs in haka, traditional siva (dance) and tapped out rhythmic beats of the island drums.
Kelston High's Pasifika dean, Margaret Simei-Afamasaga, said the boys had been rehearsing for the past five weeks.
"For a lot of them, it's about identifying with their culture. A lot of our boys are New Zealand-born and don't speak the language or don't know the culture -- and this is the only way they can connect."
Head boy Levi Farrell, 17, said joining the kapa haka group helped him to express his pride in his Maori culture, but also appreciating others.
"A lot of groups go to Polyfest for the win. But we're just doing it for the love of the culture."
The manaia (key male dancer) of the Samoan group, Elton Letoga, said his aim was to dance gracefully -- but in a manly way.
"You're representing your family, your culture, your school and your friends. I want to represent Kelston well and just want to perform with the brothers."
The festival -- which starts tomorrow -- was established in 1976 and involved only four schools then: Seddon High (now Western Springs College), Aorere College, Mangere College and host Hillary College (now Hillary Collegiate).
This year there are 64 schools participating and a record 228 cultural groups performing. The event now also includes speech competitions and students can earn credits towards their NCEA certificates.
Polyfest director Theresa Howard said the record number of groups involved this year was because of the recognition within schools that the festival was helping students engage with their community, family and peers in a unique and disciplined way.
ASB's head of community and sponsorship, Mark Graham, said: "We've been involved with Polyfest for more than 30 years and it's always a cultural highlight for us.
"The fact that it continues to grow in popularity and involvement each year speaks volumes of Auckland's multicultural landscape."
POLYFEST 2016
• 41st year. Established in 1976.
• More than 9000 students on stage.
• 228 cultural groups.
• 64 schools.
• 80,000 spectators expected over 4 days.
NEED TO KNOW:
When: Starts tomorrow through to Saturday
Where: Manukau Sports Bowl, Te Irirangi Drive, South Auckland
Cost: $5. Preschoolers free.
Must know: Only sealed water bottle/ drinks allowed. Contemporary & traditional foodstalls inside. Portaloos available.
Don't forget: Water bottle (free water inside), hats, sunscreen.
Parking: $5 parking available, but limited. Street parking avail, but carpooling recommended.
For group performance times visit: www.asbpolyfest.co.nz