Sixers stand-in skipper Alyssa Healy won the bat flip and sent Perth into bat.
Former Sixer Amy Jones got the Scorchers off to a fast start, before she was brought undone by the bowling of Marizanne Kapp for 16. However, Meg Lanning (28 off 28) and Georgia Redmayne (17 off 18) kept the momentum going for the home side as they set a steady platform for the back end of the innings.
Some tidy bowling in the middle over from Sixers spinners Dane van Niekerk (1/24 off 4) and Ash Gardner (1/13 off 2), as well as some elite fielding from Lauren Smith stemmed the flow of runs temporarily, before the big hitting Nat Sciver (52 off 37) and Heather Graham (25 off 14) teamed-up to guide the home side to a competitive total of 5/152 from their 20 overs.
In response, the Sixers suffered an early blow, losing Healy in the first over for 2. Hollie Armitage (11 off 14) and Ash Gardner (12 off 16) attempted to steady the ship, but the resistance was short lived, with wickets continuing to tumble at a steady rate.
Fresh off scoring back-to-back half-centuries, Marizanne Kapp (19 off 17) attempted a rescue mission, but her efforts were in vain as the required run rate continued to climb. Lauren Smith's late cameo and highest WBBL score of 36 not out off 35 balls provided the visitors a level of respectability on the scoreboard, but the mountain proved too difficult to climb.
The loss was the Sixers third in a row and leaves the side in danger of slipping outside of the top four, with three matches remaining.
The Sixers are back in action against the Scorchers at Lilac Hill at 1pm AEDT tomorrow.