The Sparks still had an outside chance of reaching the final but needed to win the double-header against Canterbury and for other results to go its way.
But Canterbury proved too good, stringing together convincing wins.
That left Otago in last place, with three wins from 10 matches.
In a rain-affected game yesterday the Sparks posted a reasonable total of 122.
The game had been reduced to 25 overs but Canterbury had no problem overhauling the total, with openers Frankie Mackay (39) and Michelle Mitchell (24) combining in a useful 53-run stand.
Megan Kane top-scored for Otago with 39 and Lucy Foote was undefeated on 25.
Clare Taylor took four for 14 from a tidy five-over spell.
On Saturday, Canterbury posted a challenging total of 225 for eight, thanks to a hard-hit innings from Amy Satterthwaite.
The all-rounder scored 74 off 80 deliveries and then took four for 38 to seal the 94-run victory.
Sarah Tsukigawa was the pick of the Otago bowlers.
She went wicket-less but conceded just 36 runs from her 10 overs.
Amanda Green also bowled well, with one for 22 from seven overs.
Katey Martin got the Sparks' reply off to a lively start, cracking 32 off 26.
But her departure sparked a collapse.
Having removed the dangerous Martin, Satterthwaite struck again when she cut short Tsukigawa's promising innings of 22.
Spinner Frances Mackay helped polish off the tail with three for 10 off 3.4.
