After King's unbeaten 33 off 14 balls lifted the Scorchers to 8-166, Amy Edgar's career-best 4-19 reduced the Sixers to a spluttering 9-130 in reply on Tuesday night.
Skipper Ellyse Perry (59) was the only Sixer to make any impression whatsoever against a stifling performance from the Scorchers' tweakers, offspinner Edgar being well supported by legspinner King (2-17).
The Scorchers (3-2) moved up to third position after notching their seventh victory from their past nine starts against the Sixers (1-4), who remain at the bottom of the points table.
Ellyse Perry scored 59 for the Sixers but lacked support as the Scorchers won in Perth by 36 runs.
Beth Mooney (32) and Chloe Piparo (20) combined for a quickfire 53 for the first wicket for the home side before Amy Jones (28) and captain Sophie Devine (26) stroked neat cameos.
Ash Gardner (3-38) moved to the top of the top of the competition's wicket-taking leaderboard (10 at 14.7), her crafty spinners and some magnificent outfielding from the visitors sparking a 4-24 Perth collapse.
King came in at No.8 and blasted the best knock of her WBBL career before impressing with the ball, dismissing Gardner for a first-ball duck and snaring the key scalp of Perry.
NZ great Suzie Bates' poor tournament continued, battling for timing and ultimately out slogging as the Sixers never were able to get the asking-rate under control.
Bates (18), Erin Burns (2), Chloe Tryon (16) and Mathilda Carmichael (14) all fell to the probing Edgar, who proved difficult to get away.
Perry struck 10 boundaries in a typically classy knock but when she holed out to opposite number Sophie Devine in the deep, the Sixers' faint hopes went with her.
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