Holden took three for 13 to help restrict Northern to 88 for nine and then added an undefeated 23 from 24 with the bat.
Holden had ample support with the ball. Rookie left-armer Kate Heffernan took two for 15 and spinner Leigh Kasperek claimed two for 11.
England international Beth Langston went wicketless but only conceded nine runs from her four-over stint.
It was a strong performance from the Sparks bowlers.
"Once they lost two or three wickets we knew they wouldn’t keep going ... because they are an inexperienced team who are rebuilding," coach Warren Lees said.
"But I think they showed some good signs for the future."
Otago’s batting was not terribly convincing, though.
The home side was tentative early and openers Kasperek and Millie Cowan struggled to get under way.
Cowan ran out of patience and tried to hoick the ball into the leg side but dragged it on to her stumps for four.
Kasperek dispatched a confidence-boosting drive to the boundary in the sixth over and was suddenly away. She hit another two fours in the over to get the scoreboard moving.
But having finally found the middle of the bat, she top-edged a sweep shot and was caught at backward square leg for 27.Polly Inglis came and went for 10 and Katey Martin’s dismissal for 14 would have given Northern hope, had it a few more runs to defend.
Holden, who looked the most comfortable of the Otago batsmen at the crease, guided the side towards victory.
Earlier, Northern Districts made a reasonably sedate start but accelerated in the sixth over, whacking Georgia Clarke for 18 runs.
Otago had a spot of bad luck, though, when a throw at the stumps deflected off opener Natalie Dodd and ran away for a bonus four runs.
Heffernan secured the initial breakthrough in the next over, nicking out Katie Gurrey for 19. Then Dodd made an error, hitting a catch to midwicket. Blakely made about 20m to take the catch.
The innings came unhinged further when Heffernan, in just her second twenty20 match for Otago, cleaned out Samantha Curtis with a cracking delivery.
Then Brooke Halliday was making her way back to the dressing room two deliveries later, in a carbon copy of Dodd’s dismissal.
Holden had two for four from her opening two overs and almost had a third when Bernadine Bezuidenhout lobbed a shot to midwicket.
It fell in the gap and she survived, only to be bowled by the same player a little later.
The visitors continued to capitulate, slumping to 73 for eight. Kari Carswell was run out off the last ball for 10 to complete a miserable innings for Northern.The sides will play back-to-back one-dayers at the venue today and tomorrow.
In the other matches, Canterbury beat Central Districts by 31 runs but the one-day game between Auckland and Wellington was abandoned.
● The Canterbury Kings beat the Northern Knights by nine runs in a men’s twenty20 match at Hagley Oval in Christchurch yesterday. Black Cap Tom Latham blasted 82 runs off 57 balls for Canterbury, which reached 161 for seven.
Scott Kuggeleijn (38 not out) was the best of the Knights batsmen who got to 152 for seven in their chase.
