Veteran wicketkeeper-batswoman Katey Martin tried to drag her side through to a win against Auckland at Eden Park Outer Oval yesterday.
With an ounce more support it might have been enough.
But when she holed out in the deep for 44, the Sparks' shallow batting pool had been drained.
The visitors were only chasing a modest tally.
Otago spin duo Eden Carson and Sophie Oldershaw teamed up to take four wickets. And Emma Black produced the standout performance, nabbing four for 14 to help bowl the Hearts out for 123.
But a glacial beginning to the reply and a steady stream of wickets saw the Sparks collapsed to be all out for 96 and lose by 27 runs.
Otago should have upset Canterbury at Hagley Oval on Saturday but did not have the batting depth to seal the win.
The side has been without White Ferns all-rounder Hayley Jensen for the past three games, and Suzie Bates was ruled out for the season with a shoulder injury.
Earlier, Auckland rebounded from the early loss of Lauren Down to muscle its way to 49 for one at the end of the powerplay.
Opener Katie Perkins, in her 150th T20 game, had got a start. But before she could really get going the right-hander was bowled for 23 by Carson.
The off-spinner struck again. This time she trapped Anna Peterson in front for a promising knock of 31 from 26.
Bella Armstrong, who survived an early scare, teamed up with Holly Huddleston to battle through the middle overs.
Black returned and broke the partnership. She swung one back and bowled Armstrong for 19.
Saachi Shahri perished in the same over. Black's inswinger was too good for her.
Huddleston's response was to crunch Gemma Adams for a couple of sixes. But she got a top edge later in the over and Martin made a running catch over her shoulder to dismiss her for 23.
Leg spinner Oldershaw grabbed two wickets in the next over to knock the stuffing out of Auckland's lower middle order.
Otago made a slow start to its innings and lost a couple of early wickets.
There were just two boundaries hit the first 10 overs and one of them was an edge.
That left Martin and Millie Cowan with some catching up to do.
But Cowan got run out for 10 which heaped more pressure of the Sparks' middle order.
Caitlin (7) Blakely came and went quickly.
Olivia Gain played a across the line and was adjudged lbw.
No-one could stay with Martin and she eventually succumbed to the pressure.
The Sparks will complete their tournament with a home game against Northern Districts on Saturday.
