The win reversed the result of yesterday's meeting between the two sides, in which the Thunder triumphed by one run at Lilac Hill in front of another bumper crowd that neared 5000.
The Scorchers remained in fourth place on the table, but the win ensured they kept touch with a finals group caught in a log-jam, while preventing the Thunder from creeping further ahead.
The Thunder (12pts) is the only Club in the top four with a clear points lead, with the Sydney Sixers, Brisbane Heat and Scorchers all equal on 10pts and separated by net run rate.
The Scorchers won the toss, electing to bowl, and were keen to atone for the nailbiting loss to the Thunder yesterday and immediately had their opponents on the back foot, with the returning Katherine Brunt (1-13(4)) striking four balls into the game.
Brunt, who recovered from a back injury, found a way through opener Rachel Priest's defences to dismiss her for a second-ball duck and have the Thunder 1-1.
The visitors were put under further pressure when national captain Rachel Haynes was caught off Nicole Bolton (1-20(4)) for just eight.
The Thunder were in dire need of a lasting partnership at 2-15 and they found one in skipper Alex Blackwell (81 not out) and Stefanie Taylor (31 off 45), who moved their side to 3-128 by the time the latter was castled by Piepa Cleary (1-20(3)).
However, despite the solid pairing and the Scorchers taking only one more wicket for the innings, the duo struggled to find boundaries, with the Scorchers rotating through seven bowlers and proving miserly as they recorded 51 dot balls to hold the Thunder to 4-134 after 20 overs.
The Scorchers entered the pursuit of the modest tally with intent and did not relent, despite a pin-point run-out removing captain Elyse Villani (nine from nine) early in the chase.
Bolton (28 from 22) laid a solid foundation before holing out off Maisy Gibson (1-18(4)) at 2-86, with the Scorchers bringing up the team ton in just 65 balls.
Some wayward bowling from the Thunder did not help the visitors' cause, with 21 sundries - the majority of which came in the first half of the innings.
Tightening their deliveries reduced the Scorchers' run-rate, but the hosts remained in control, with England's Natalie Sciver (61 off 50) leading the way.
The Thunder had a chance to remove the all-rounder, putting her down at mid off on 48, but failed to capitalise on the opportunity.
It ensured the Scorchers continued to cruise towards the 135 for victory, with Sciver pouncing on an over-pitched delivery from Lisa Griffith (0-25(2.1)) and whipping it to the backwards-square boundary to end the innings at 2-136 in 18.1 overs and record the eight-wicket win.
The Scorchers next take on the Adelaide Strikers on Saturday and Sunday in a double-header weekend at Treagar Park, Alice Springs, with the Saturday game followed by the KFC Big Bash League game between the Clubs at the same venue.