Brisbane will be sweating on the fitness of Georgia Redmayne after the golden bat leader injured her hamstring during her side's 33-run WBBL win over the Perth Scorchers.
The Heat posted a competitive 7-153 at Lilac Hill on Wednesday before restricting the Scorchers to 8-120 in a disappointing batting display from the defending champions.
The result rocketed Brisbane from third into top spot while the fourth-placed Scorchers have lost two games on the trot and now face a fight to make the finals.
The Scorchers are two competition points ahead of fifth-placed Hobart, but the Hurricanes have two games in hand and a better net run-rate.
Brisbane's victory over Perth was significant in the race for the prized top spot, but the injury to Redmayne is a major worry just two weeks out from the finals.
Redmayne winced in pain after getting down on a knee to play a shot early in the seventh over.
The 28-year-old continued to bat, but her hobbling between the wickets meant the Heat had to settle for singles several times when two runs were on offer.
Redmayne cracked a boundary to finish the 11th over, but she was called off by the doctor immediately after.
Despite being forced to retire hurt, Redmayne's 28 off 27 balls was a team high.
Redmayne has scored a competition-high 333 runs this season and it remains to be seen how serious the injury is.
"She's a pretty special player, but we do back the depth of our squad," Heat allrounder Nicola Hancock said.
"Ellie Johnston came in (to replace Redmayne as wicketkeeper).
"The first game this season Ellie scored a 50. We definitely back her with the bat and with the gloves."
The Scorchers slumped to 4-47 in a poor start to their run chase.
Openers Beth Mooney (eight) and Sophie Devine (two) fell cheaply, with Chloe Piparo (seven) and Marizanne Kapp (five) also failing to have an impact.
The loss would have been far worse if it wasn't for the efforts of Maddy Green, who scored 58 off 53 balls before being run out in the final over.
"We know we haven't played our best cricket and that's certainly to come, so I'm looking forward to that," Green said.
The form of captain Devine is of particular concern to the Scorchers.
The 33-year-old has scored just 119 runs at an average of 14.9.
Her strike-rate of 99 this season is also far below her usually lofty standards.
Devine also dropped a catch in the deep on Wednesday and conceded 12 runs off her first over, but she rebounded to finish with 1-27 and a crucial run out.