Perth have rallied superbly to kill off the Melbourne Stars' run chase and convincingly win their knockout WBBL final by 28 runs.
After briefly holding top spot, the Stars' season ended on Tuesday night at the WACA ground with four-straight losses, while the Scorchers have won five of their last six.
Perth will now head to Sydney to play the Sixers in the challenger final and the winner will face top side Hobart in Saturday night's title decider.
Melbourne needed a record WBBL finals run chase to win after the home side made 5-173, but reached 1-86 at halfway and looked capable.
They then lost 8-59, including the crucial wicket of Meg Lanning, and ended on 9-145.
The Stars' chase had a disastrous start when Rhys McKenna was run out for seven. Lanning only scored three from her first 13 deliveries as Chloe Ainsworth had an excellent opening spell.
Lanning had made 11 when she tried to sweep Alana King and was nearly out stumped, with the ball rebounding off 'keeper Beth Mooney and just missing the stumps.
But steadily, Lanning and Amy Jones put the pressure back on Perth. They combined for a 87-run stand that took them to 1-101 in the 13th.
Perth did not panic, rallying after halfway as spinners Amy Edgar and Ruby Strange in particular bowled tightly.
Eventually the pressure told and King had Jones stumped for 43 from 33 balls.
Lilly Mills then took two wickets in an over as the momentum swung back to Perth.
As long as Lanning was in, the Stars were a chance and Ainsworth dropped a straightforward chance off her when the key to Melbourne's chances had made 41.
But Ainsworth had the perfect response at the start of the next over, having Lanning caught behind to leave Melbourne's chances shot at 6-126.
Lanning top-scored with 49 from 45 balls, while King, Sophie Devine and Mills took two wickets apiece..
After Perth won the toss, openers Katie Mack and Mooney posted the Scorchers' highest partnership of the season.
Their 107-run stand threatened to take the match away from Melbourne, before Rhys McKenna made the breakthrough in the 13th over.
She dismissed Mack, caught by Maisy Gibson, for a top score of 52 from 39 balls.
Mooney, who looked set for another big score, fell in the next over for 45 when Gibson also caught her off Kim Garth.
The Stars were right back into the game, especially when danger player Sophie Devine came in at No.3 and only managed one before McKenna claimed her second wicket. That left Perth 3-128 in the 16th over.
But Freya Kemp made the most of two dropped catches from Georgia Prestwidge. She belted 35 from 19 balls, with three fours and two sixes, in a crucial knock.
Gibson took her third catch of the innings as Stars captain Annabel Sutherland dismissed Kemp for her 100th WBBL wicket.
Gibson also snared 1-15 from two overs and McKenna was the pick of the Melbourne bowlers, claiming 2-26 off three overs.
