They were beaten by 75 runs by the ruthless Wellington Blaze at Seddon Park this afternoon.
Led by White Ferns star Sophie Devine, Wellington scored 175 for four.
Devine blasted 92 off 62 balls, hitting 10 fours and five sixes.
She and Maddie Green (55 off 35) added 110 for the third wicket.
The Sparks’ chase never recovered from the early loss of talisman Suzie Bates.
Otago was all out for 100 in the 18th over.