Despite falling by five wickets to the Sydney Thunder at Lilac Hill on Saturday, the Scorchers finished the regular season in second spot.
Perth won the toss and elected to bat, setting a total of 4-131.
This score was always going to require the Scorchers’ bowlers to be at the top of their game, but the Thunder eventually chased the total down at 5-134 with five balls to spare.
Get in front of tomorrow's news for FREE
Journalism for the curious Australian across politics, business, culture and opinion.
READ NOWThe home team built their innings off the back of reliable former skipper Nicole Bolton (53 off 43), whose composed knock was highlighted by a six to bring up her half-tonne.
Bolton had been well supported by current captain Suzie Bates (28 from 36), with the pair top scoring for their side and having compiled a 69-run partnership by the time the latter fell at 2-99. A closing-over flurry from Katherine Brunt (17 off 11) helped hoist the Scorchers to their 4-131.
MORE: Doughnuts to help fuel charity ride
MORE: Aboriginal elder says we must use Australia Day to move forward
MORE: Junior football club on the mend after money theft
The reigning WBBL champions the Thunder appeared formidable in their chase, losing just two wickets in their march past 100, with Player of the Match Stafanie Taylor (62 off 54) and Alex Blackwell (26 off 20) compiling a 57-run partnership for the second wicket.
Midland-Guildford’s Elyse Villani, the Scorchers opening batter, provided the surprise of the day, snaring three wickets in an over with her part-time spin.
This slowed the visitors’ momentum, but the Thunder were too strong, as they needed just 16 off the final 18 deliveries for victory.
Captain Bates called on Villani, who had Taylor hole out at mid-wicket, then trapped Nicola Carey for duck next ball, before having Naomi Stalenberg caught-and-bowled for a duck three balls later.
However, the Thunder had already edged too close to victory, with Erin Osborne hitting a four to secure the win for the visitors.
The Scorchers play the Brisbane Heat in the semi-final today at the WACA, which will get under way from 11.40am.