Mooney hit 12 boundaries and brought up her half-century off 27 deliveries, striking the ball crisply square of the wicket with a flurry of pulls, sweeps and cut shots.
She is now the leading run-scorer for the tournament, having passed 400 runs in 10 of the 11 seasons of the WBBL and reaching 386 runs in the other.
“I’m pretty lucky I get to open the batting and face a lot of balls,” Mooney said.
“I’ve had a lot of help along the way, a lot of conversations with different coaches and a lot of people throwing me balls.
“It’s always nice when you’re hitting them out of the middle and you can go back to what’s worked for you in the past.”
Katie Mack offered support with 40 in a 66-run opening stand with Mooney, but the Queenslander then took over the innings with no other Scorcher passing 20.
Needing to pull off the highest successful finals chase in WBBL history, the Sixers looked in the contest with Sophia Dunkley and Ellyse Perry firing early.
But when Perry hit King straight to mid wicket on 29, the game swung.
Kerr (42) and Gardner (26) offered the hosts hope, but King again ensured that would be a false dawn by removing both Gardner and then Maitlan Brown in her next over.
The result means the Sixers’ title drought will extend to eight seasons, after the star-studded club played in the first four WBBL finals.
