Most of his family, including mum Talitha Webster, went along to support him.
"It was a fabulous night watching a wide range of dancing and singing. It was a cool night watching our youth, our babies on stage," Ms Webster said.
It was unexpected win, said Poppy Langdon, 10, who took out the dance section.
"I was very happy."
She said she danced to Strong by London Grammar.
"It's a really nice song to dance to...I will enter again next year, it was really fun and I'm just starting to do competitions."
Her mum, dad and sister supported her on the night.
Co-organiser and chief judge Mercia-Dawn Yates said it was a fantastic evening.
"It was a very successful finale with a high calibre of talent taking out the top seven prizes."
Thirteen competitors, from 8 to 18, battled it out for the top spots.
Prizes for final winners in each category were $1000 Noel Leeming gift vouchers for winners and $500 vouchers for runners-up. There was also a People's Choice prize of $250.
All prizes were donated by the Rotorua Lakes Council.
Paretoroa said he planned to spend his voucher on an iPad for when he started Rotorua Boys' High School next year.
Tamati Coffey was MC for the night and said the event went "beautifully".
"It was a privilege to be the MC. As you can expect backstage it was a mixture of nerves and excitement, a mix of emotions."
There was a range of ages and kids from different schools taking part, he said.
"It was a packed house and everyone got behind the performers ... it was a great event for the community by the community."
It was the second year of the competition; a collaboration between the Rotorua Library and Nga Pumanawa e Waru.
Lois Haddon, acting Rotorua Library director, said partnering with Nga Pumanawa e Waru in putting together the "uplifting occasion" and seeing "all of the talented young performers truly shine" was a major highlight for the library staff.
Matariki Star Search 2017 Finale
Dance:
1. Poppy Langdon (10, Kawaha Pt Primary)
2. Madelyn Skilton (18)
Singing:
1. Paretoroa Webster-Tarei (12, Rotorua Intermediate School)
2. Christian Te Whare & Kahu Durie (15, Rotorua Girls' High School)
Nga mahi a Rehia o te Ao (Global performing arts) :
1. Ruaeo Te Moni (11, Te Wharekura o Ngati Rongomai)
2. Ahipukahu Edmonds, Te Ahu Paenga (Te Kura Kaupapa Maori o Ruamata) & Ngarangimihi Panapa (Rotorua Primary)
People's Choice:
Ruaeo Te Moni (11, Te Wharekura o Ngati Rongo Mai)