Jared Tutty, in his debut for the Bay of Plenty second XI, bowled downwind, caused early problems for the Northland top order and was rewarded with his first wicket for the side.
Singh and Sean Wakelin battled into the wind, before the introduction of Bay of Plenty leggie Iman Singh paid dividends. The Tauranga Boys' student relished the tough conditions to take three wickets at a cost of 39 runs.
At the other end, Brody Gilroy troubled the Northland batsmen with seam and pace to take a five wicket bag.
The Te Puke premier player bowled extremely economically and was rewarded with 5-26 - his best bowling figures for Bay of Plenty Development.
Northland were bowled out for 136, to give Bay of Plenty their second win from two games this season.
"We now look forward to squaring off against Hamilton in two weeks time, who will be our toughest opponents in the competition, with the encounter likely to decide the Basil McBurney trophy," Williams said.
Bay of Plenty 211/8 (Christian MacDonald 60, Sean Davey 48, Cam Neal 25, Stephen Crossan 21; M Taylor 3-33, S Walker 2-25) defeated Northland 136 (J Kose 30; Brody Gilroy 5-26, Iman Singh 3-39).