The defensive pressure through the mid-court - where centre Myia Hetaraka and wing defence Iva Livani picked up five intercepts between them - proved a strength to their game against Epsom Girls' while goal keep Nanise Waqaira was again strong at the back.
They led 14-11 at half-time with shooters Leehava Saverio and Lasalle Lefale sharing the load in the circle.
Howick also showed their superiority with rebounding picking up four more than their opponents to give them the edge.
It was a tough road to the final for Saint Kentigern after falling early to Howick, setting them on a path for a rematch of last year's grand final against Mount Albert Grammar School (MAGS) in pool play.
The match-up went some way in determining which side would finish top of their pool and Saint Kentigern led from the opening quarter for a narrow 34-32 win.
They then had to hold their nerve in a tense battle with St Mary's College of Wellington to book their place in the grand final, winning 29-26.
Saint Kentigern's front line stood out with Beko Netball League player Ashleigh Garner shining at goal attack, netting 24 of her team's goals. New Zealand Secondary Schools mid-courter Tayla Earle controlled the game through the middle with her feeding into the shooting circle and also nabbing three intercepts and deflections. Saint Kentigern put up 15 more goals than their opponents but struggled with their radar at times.
The play-off for third and fourth place will see Palmerston North's Manukura take on Epsom Girls' while Waikato Diocesan meets MAGS and St Hilda's Collegiate will play St Mary's for seventh and eighth place.
Meanwhile, St Paul's Collegiate and Sacred Heart College of Lower Hutt topped their respective pools and will meet to determine ninth and 10th place.
Sacred Heart College edged into the top play-off position after beating Ashburton College 40-25 in a tightly contested pool while St Paul's went through the round unbeaten.
The final will be played at 1.40pm.
New Zealand Secondary Schools Netball Championships - Day 3 Results
St Paul's Collegiate School 43 v 32 St Margaret's College
Sacred Heart College 37 v 31 St Andrew's College
Ashburton College 29 v 27 Palmerston North Girls' High School
Christchurch Girls' High School 28 v 40 Queen Margaret College
Howick College 40 v 21 St Hilda's Collegiate School
Mount Albert Grammar School 32 v 34 Saint Kentigern College
Manukura 46 v 26 St Mary's Wellington
Epsom Girls' Grammar School 33 v 26 Waikato Diocesan School for Girls
St Margaret's College 39 v 26 Queen Margaret College
Palmerston North Girls' High School 28 v 35 St Andrew's College
Sacred Heart College 40 v 25 Ashburton College
Christchurch Girls' High School 22 v 40 St Paul's Collegiate School
Howick College 33 v 29 Epsom Girls' Grammar School
Saint Kentigern College 29 v 26 St Mary's Wellington
Manukura 39 v 34 Mount Albert Grammar School
Waikato Diocesan School for Girls 42 v 23 St Hilda's Collegiate School