The Sparks spent Saturday night at the top of the one-day competition table after recording a 22-run win against Wellington.
But the Blaze bounced back to beat the Sparks by nine wickets yesterday.
The fixture became a bit of a lottery when poor weather forced the players from the field with the Sparks 63 for two after 15.2 overs.
Wellington had got on top by getting rid of the dangerous Suzie Bates for 33 and Sarah Tsukigawa had been bowled by Michelle Bunkall for 21.
The match was reduced to a 20-over affair and the Sparks lost a further five wickets in a mad scramble for the addition of just 23 runs.
Wellington chased an adjusted target of 116 and cantered to victory with Rachel Priest (43) and Sophie Devine (51) combining in a unbroken stand of 91 for the second wicket from just 70 deliveries.
On Saturday the rain let up long enough for Otago to record its third consecutive win. The Sparks posted 131 for four and restricted Wellington to 109 for eight in a reduced 20-over game.
Bates scored more than half her side's runs, notching 72 before she was run out. Her innings included 10 fours and she raised her 50 from just 42 balls.
She also combined with Tsukigawa (18) in a solid 61-run opening stand, and Katey Martin chipped in with 16 runs from 17 deliveries.
Devine was the standout performer with the ball for Wellington, taking one for 11 from her allotment of four overs.
Legspinner Emma Campbell did the damage for Otago. She took three for 21 and Victoria Abbott and Lisa Kasperek grabbed two apiece.
Priest top-scored for Wellington with 50 at the top of the innings. Devine made 21 and Lauren Ebsary added 15. None-one else was able to reach double figures.
With three wins from four games, Otago is in second place with 14 points.
Its next match is a twenty20 game against Central Districts at Molyneux Park on January 2.
• Otago's HRV Cup match against Wellington at the Basin Reserve yesterday was abandoned without a ball bowled. Both sides picked up two points and that was enough for Otago to bump
Northern Districts off the top of the competition table. While the Volts and the Knights have 16 points apiece, Otago takes top spot as it has a superior net run rate.
Northern has a game in hand and can overtake Otago with a win against Canterbury in Mount Maunganui on Thursday.
Otago's next match is against Auckland, at Eden Park on Friday. It is televised on Sky.
