The Sydney Sixers' WBBL|07 finals hopes are hanging by a thread after falling to Brisbane Heat in a low-scoring affair under lights in Mackay.
The Sixers' big guns failed to fire with the bat as they scratched their way to 7-91 from their 20 overs, and although their pace attack led by Lauren Cheatle (3-16) ensured the Heat's chase was not straightforward, the Brisbane club nonetheless reached their target with 35 balls to spare and three wickets in hand.
Courtney Sippel (2-12) removed Alyssa Healy and Ashleigh Gardner in a double-wicket maiden to hand the Heat a dream start in the powerplay; Healy looked perplexed to be given out caught behind but was forced to depart for four, before Gardner's stumps were rattled five balls later.
Ellyse Perry scored just two runs from 12 deliveries; caught behind off the bowling of Jonassen, and Shafali Verma (7) was also dismissed cheaply, leaving the Sixers 4-34.
Nicole Bolton dug in for a crucial 25 off 31 and it took a stunning one-handed catch from Mikayla Hinkley to dislodge the former Australia batter, while India spinner Radha Yadav added an important 17 not out to help the Sixers to 7-91.
Just three boundaries were scored by the Sixers across the 20 overs, the equal-lowest for a completed innings in the competition's history.
Jonassen reclaimed the title of 'golden arm', moving to the top of the wickets table after snaring 3-15.
The Sixers quicks found plenty of movement under lights as they sought to defend the small total, with Cheatle claiming the key scalps of the top three, Grace Harris (0), Georgia Voll (13) and Georgia Redmayne (19).
Maitlan Brown chimed in with a peach of a delivery to bowl Annake Bosch (1), leaving the Heat wobbly at 4-37 inside the powerplay.
Heat skipper Jonassen (15) sought to settle the chase, hitting two boundaries before being removed by Gardner.
Laura Kimmince (16) got off the mark with a boundary and while Perry thought she had removed the dangerous batter on nine, she was found to have overstepped.
Kimmince smacked another four and a six, and while she was dismissed with seven runs required, and Hinkley (11) fell the following over, Nadine de Klerk (5no) and Courtney Sippel (2no) saw their side over the line.
The loss leaves the Sixers two points outside of the top four with just three games remaining, and they need other results to fall their way to make a return to the semi-finals.
The Heat meanwhile moved to second on the table and have a chance to reclaim top spot against Adelaide Strikers on Sunday morning.