The Spirit posted 218 for seven after struggling early on in the one-day game. That total proved plenty, with Otago dismissed for 138 thanks largely to a fabulous bowling performance from Nicola Browne.
The White Ferns all-rounder took five for 31 to seal the 80-run win. It was her maiden five-wicket bag in one-day cricket and she achieved the milestone in style, bowling four of her victims and picking up the key wicket of Katey Martin with her first ball.
While the final result was comprehensive, Otago actually had a golden opportunity to register its opening win this summer but its grip on the game slipped thanks to a marvellous partnership.
Rhiana Vincent and Morna Nielsen rescued their side's innings with a 122-run stand for the seventh-wicket.
Northern had slumped to 86 for six after 27 overs and was not at all well-placed to push on and post a competitive total.
Kate Stiven (two for 42) and Tanya Morrison (three for 16) had picked up five wickets between them and Rebecca Henderson had seemingly removed that last thorn when she trapped a resistant Natalie Dodd (25 from 72) leg before wicket.
But Northern clawed its way back into the match through some determined batting from Vincent (41 from 75). She was was prepared to occupy the crease the accumulate runs while Nielsen played a plucky innings.
The 21-year-old whacked seven fours and a six in a sparkling undefeated innings of 79 from 66 deliveries. It was her first time past 50 in 36 one-day games.
Otago's reply got off to the worst possible start, with Martin dismissed first ball. Kylie Crowley and Lisa Grant offered precious little resistance, and Susie Burrows and Natasha Miles both registered ducks as Otago stumbled to 45 for five.
New Zealand and Otago captain Suzie Bates and the in-form Victoria Abbott tried to conjure a miracle. Abbott scored an undefeated 53 from 37 in a twenty/20 match on Tuesday and hit a brisk 27 before she was bowled by Vincent. Bates was trapped lbw for 45 in the next over, effectively ending all hope.
The teams play a twenty/20 game this morning.
• Zimbabwe captain Brendan Taylor piloted Wellington to a seven-wicket win over Auckland in their HRV Cup clash at the Basin Reserve yesterday, APNZ reports.
On the back of 53 from 37 balls from Taylor and James Franklin's 68 from 38 balls, the home side coasted to victory with nine balls and seven wickets to spare.
Wellington skipper Grant Elliot, with three for 16 with his right-arm medium-pacers, and offspinner Jeetan Patel, with two for 24, had limited Auckland to 157 for nine.
