The Otago Sparks slumped to back-to-back losses to Auckland in Invercargill during the weekend.
The Hearts backed up an eight-wicket win on Saturday with a three-wicket win yesterday.
The loss has left the Sparks winless after four games and anchored at the bottom of the competition standings.
The team is well down on firepower this season.
Star player Suzie Bates is out for the summer with a shoulder injury. Veteran wicketkeeper-batswoman Katey Martin was unavailable for the first four rounds and White Ferns all-rounder Hayley Jensen is in Australia and is not expected to be available for the Sparks until early next year.
In their absence, the Sparks have struggled to put in a complete performance.
They have shown patches of form but were outplayed by their opponent in both games.
Otago was asked to bat first yesterday and could only muster a modest tally of 154.
Extras were the biggest contributor. They accounted for 41 runs. The next highest scorer was Polly Inglis with 23. Eden Carson (17), Bella James (13), Olivia Gain (12) and Sophie Oldershaw (10) got out of single digits, but it was was dismal batting effort.
Jane Barnett stood out with four for 31, and Fran Jonas took two for 28.
Auckland lost three late wickets but had seized control of the game with a solid effort by three of the top four batswomen.
Regina Lili’i (45) and Katie Perkins (39) anchored the chase and opener Lauren Down (24) helped get the innings off to a solid start.
The Hearts were cruising at 150 for four, but lost three wickets for four runs.
Emma Black picked up two wickets in two balls and her two for 27 from nine overs was a good return.
Oldershaw and Molly Loe grabbed two wickets apiece as well.
The opening game on Saturday was reduced to 24 overs apiece.
Caitlin Blakely top scored with an undefeated 44 from 62 deliveries to help her side post 116 for five.
Opener Millie Cowan chipped in with 18 and Inglis added a valuable 22 from 19 balls to inject some late momentum into the innings.
But visitors ran the tally down easily enough. Downs (40) and Bella Armstrong (62 not out) put on 63 for the second wicket to move their side into a commanding position.
Armstrong was particularly aggressive during her undefeated knock. She clouted one six and nine boundaries in just under an hour at the crease.
Black was clearly the best of the Otago bowlers. She took one for eight from three overs and went for fewer than three runs an over on a day when most of the Sparks’ attack struggled to contain the run rate.
In the other matches, Canterbury beat Northern Districts by 84 runs in Whangarei on Saturday and by 35 runs yesterday.
In Levin, Central Districts crushed Wellington by eight wickets on Saturday but was beaten by two wickets in the return match yesterday.
