They continued to look better as the game went on and, with four minutes left to play, Howick had the largest lead of the match so far, 28-22. They maintained their intensity and extended their lead further to win 33-25 and lift the trophy.
In a victory built on defence and disrupting St Kentigern's offence, Howick's back three of goal keep Nanise Waqaira, goal defence Shalom Setu-Veve and wing Iva Livani combined well with the trio picking up five intercepts and nine deflections between them.
Howick coach Adelita Sotutu said her side's performance this week was "phenomenal".
"It was a dream, it was our goal to get here to nationals and it was pretty surreal sitting here on Tuesday, at nationals for the first time. To wake up this morning and actually believe we were on the court for finals is just a dream come true - the fairytale," Sotutu said.
She was watching the clock closely at the end of the final.
"Watching the clock, looking at the times, seeing the score - the girls knew they had nothing to lose, they just had to keep playing the way they had been playing. We are a team through and through, the bench, the management, the seven on the court, we are a complete unit," she said.
Meanwhile, Manukura was third after beating Epsom Girls' Grammar School 37-30.
A strong second-quarter performance, where they outscored Epsom 15-6, set the Palmerston North school up for the win. Centre Braxton Te Rini was a standout in the middle for Manukura picking up five intercepts and feeding her shooters well.
Manukura were also bookended by strong showings from goal keeper Antonia Heihei who snaffled five intercepts and six deflections while shooter Rochelle Fourie netted 30 goals for her side and picked up five valuable rebounds.
New Zealand Secondary Schools Netball Championships Grand Final:
Howick College 33 (Leehava Saverio 20/24, Lasalle Lefale 13/13) beat Saint Kentigern College 25 (Hannah Ward 7/9, Ashleigh Garner 18/24). Quarter scores: 6-8, 15-16, 23-21, 33-25.
Final Placings
1 Howick College
2 Saint Kentigern College
3 Manukura
4 Epsom Girls' Grammar School
5 Waikato Diocesan School for Girls
6 Mount Albert Grammar School
7 St Mary's Wellington
8 St Hilda's Collegiate School
9 St Paul's Collegiate School
10 Sacred Heart College, Lower Hutt
11 St Margaret's College
12 Ashburton College
13 Palmerston North Girls' High School
14 Queen Margaret College
15 St Andrew's College
16 Christchurch Girls' High School