Earlier, New Zealand used eight bowlers against Northern Territory, whose batsmen struggled to build on their starts as seven of them scored 15 or more but none exceeded 25.
Kurtley Watson took 4-34 off his nine overs.
As top scorer in the match, Collier had struck five boundaries in his 42, scored off 70 balls.
Notably, it was against Northern Territory sides that Collier enjoyed his best success of the tour, scoring a hundred in the warmup game before the start of the Tri Series.
He had disappointing returns against the Australian and Indian Under 19 teams, as New Zealand failed to make the final.
Unbeaten India, who will host next year's Under 19 World Cup, stamped their dominance with an eight-wicket win over Australia to lift the trophy on Friday.