Revealed in an epic fireworks display, the winners' name - Kiwi Cuzzies - was spelt out in fireworks across the sky, followed by a mega slime.
This year, 7000 children entered, hoping to be a part of the series, with one other duo coming from New Zealand.
Kaha and Zion entered the competition late last year after watching the series for the first time.
Kaha said he was staying at Zion's home in the Christmas holidays when an advertisement came on the Nickelodeon channel asking people to apply for this season.
The two boys went camping the next weekend and started filming their audition tape.
"We called our team the 'Kiwi Cuzzies' so we put some Kiwi and New Zealand things in the audition, like the haka."
The duo were away filming the series at Sea World on the Gold Coast in Australia from March 16 to 22.
The 12-year-old, who had to keep the show a secret until now, said they were busy the whole time they were away.
"We had about five cameras in our faces the whole time."
Initially, Kaha said he was sceptical and surprised when they were selected for the show but his cousin was more confident.
"From the moment he (Zion) had the idea, that's just the kind of person he is."
Being part of the show was the best thing they had ever done.
"We got to meet Timomatic and other famous people. I can't really give away too much about our challenges but they were all exciting."
Kaha said he was unsure about his fame once the show aired.
When the two boys came home, their families had a welcome home party at the airport.
"It took a while to 'get back to reality' since we had been treated like stars over there," Kaha said.
"I don't think it's sunk in about being on TV yet and I am a bit nervous but I won't know until the first episode is on in a few weeks."
