The Perth Scorchers have secured top spot and direct entry into the WBBL decider after snaring a last-gasp win over the Melbourne Stars before watching the Melbourne Renegades stumble yet again.
The Scorchers beat the Melbourne Stars by four wickets on Saturday after scrambling through for a single on the last ball of the innings.
Kim Garth's underarm throw from mid-off went wide as Taneale Peschel clambered through, with the Scorchers reaching 6-123 in reply to Melbourne's 7-122.
The Renegades had the chance to retake top spot from the Scorchers, but they slumped to a 43-run loss to the Brisbane Heat on Saturday night.
It was their second loss in as many days.
Georgia Redmayne scored 71 off 51 balls and Georgia Voll added 41 off 30 as the Heat posted 5-156.
In reply, the Renegades were bowled out for 113 in 18.1 overs. with Jessica Jonassen (3-10), Nicola Hancock (2-12) and Nadine de Klerk (2-23) doing the damage with the ball.
The result saw the Heat jump to third, but they will be relegated to fourth if the Adelaide Strikers beat the Melbourne Stars on Sunday.
The Renegades held top spot for much of the season but must now be content with finishing second.
It means instead of earning a direct path into the final, the Renegades will face off against the winner of third versus fourth in what is effectively a preliminary final.
The Scorchers play the Sydney Sixers on Sunday, but they will finish in top spot even if they lose.
Saturday morning's game would have been a Perth walkover had it not been for Stars opener Elyse Villani, who belted nine fours and two sixes in her innings of 84 from 66 balls.
Incredibly, Villani was the only Stars player to reach double figures, while Heather Graham snared 3-16 from her four overs.
It is the WBBL's highest score with only one batter reaching double figures.
Perth were stuttering at 4-69 in the 14th over, but Melbourne were left to rue some poor fielding in the late overs as Mathilda Carmichael's 30 and Marizanne Kapp's 29no steadied the Scorchers.
Perth needed nine off the last over from Annabel Sutherland, but a four to Alana King and then Garth's missed chance sealed the result.
Sutherland was the pick of the Stars attack with 2-20 from four overs.
At the other end of the table, the last-placed Sydney Sixers slumped to the lowest score of the season as in-form Adelaide walloped them by eight wickets.
The Sixers were dismissed for 82 in 19.2 overs and the Strikers confirmed their finals berth when they cruised to 2-84 at Adelaide Oval on Saturday afternoon in only 10.2 overs.
Sixers stars Alyssa Healy and Ashleigh Gardner made ducks as they crashed to 6-30.
The tailenders saved Sydney some blushes and Lauren Cheatle top-scored with 16 as Darcie Brown (2-25) and Sarah Coyte (3-12) shared the spoils.
Adelaide opener Dane van Niekerk mauled the Sixers attack with five fours and a six in her innings of 33 from 22 balls, ensuring it would be a quick run chase.
In Saturday's opening Mackay game, superb bowling from Belinda Vakarewa spearheaded the four-run win for the Hobart Hurricanes over the Sydney Thunder.
Vakarewa took 3-8 from her four overs as the Thunder scored 9-143 in reply to Hobart's 5-147.
Mignon du Preez top-scored for Hobart with an unbeaten 87 from 61 balls, featuring 11 fours and a six.