Two early wickets from off spinner Aaron Ranara had Northland buzzing, but at the halfway stage Hamilton were 65 for two and in the box seat.
At drinks, coach Karl Treiber suggested trying something different by using leg spinners Quinn Pooley and Peiris, who between them had bowled just one over in the tournament. This proved a masterstroke as six wickets fell for just 20 runs.
Pooley at one stage had three wickets for one run off three overs while Peiris was equally unplayable. Hamilton looked doomed at 85 for eight but crawled their way towards the target until the thrilling finale and West becoming Northland's newest hero.
Manager Roger Kidd was delighted with the result and praised the team spirit which was crucial when things got tight near the end.
Adding to the excitement was the fact that Northland had one of the youngest teams, with seven year nine pupils available to defend the title next year.
Northland Cricket general manager Warren Marr commented earlier this year that he wanted to see Northland teams winning national tournament, and they have started to deliver.
Marr said he had a feeling a few months back that Northland would start to see some results from the work of Stephen Cunis and his coaching team.
"We're very happy with that," he said. "This is vindication of the work that has been done over the last two years. I had a feeling it might come this year but didn't want to say it because I know these things don't happen overnight. We were into our third year and I thought it was about the time we got some results."
RESULT
Northland 126 (Chamodh Peiris 28, Van Grooby 11 n.o., Hamish Kidd 10, Aaron Ranara 10; Johnny O'Sullivan 4/18, Liam Calmon 2/16) beat Hamilton 124 (Jamie Moore 33, Braydon Gaylor 31 n.o.; Quinn Pooley 3/14, Chamodh Peiris 2/17, Aaron Ranara 2/24, Caleb Boswell Smith 1/17).