The Adelaide Strikers have secured top spot while the Brisbane Heat booked a finals berth with wins in Friday's WBBL double-header.
The top four is all but set with Adelaide (18 points), the Perth Scorchers (16), the Heat (16) and the Sydney Thunder (15) likely finalists.
Brisbane and Perth have completed their minor round games.
Only a massive win and associated run-rate boost from fifth-placed Hobart (13 points) over the rampant Strikers on Sunday can displace the Thunder, who meet the Sydney Sixers the same day.
Reigning champions Adelaide on Friday night flexed their collective muscles in a five-wicket win over the Scorchers.
Perth slumped to 4-15 inside five overs and were bowled out for 104 in 19.4 overs, with the Strikers reaching 5-106 to win with 31 balls to spare.
In the afternoon game at Adelaide Oval, the Heat posted a 22-run win over the Thunder.
After the Heat made 8-160, Brisbane's Jess Jonassen took 4-26 to restrict the Thunder to 9-138.
Thunder openers Chamari Athapaththu (34 from 28 balls) and Phoebe Litchfield (23 from 21) gave the Sydneysiders a brisk start.
But they then lost six wickets in an eight-over span to lose all momentum as Jonassen turned the screws.
Earlier, Brisbane's Beth Heath made 29 from 25 balls to top score during an even batting effort.
Seven batters made more than 12 with opener Georgia Redmayne (21 from 21), Amelia Kerr (20 from 17), Laura Harris (19 from nine) and Georgia Voll (18no from eight) making handy contributions.
Thunder quick Sammy-Jo Johnson was the chief wicket-taker with 3-39 and Marizanne Kapp claimed 2-26.
In the night game, the Scorchers struggled amid an early onslaught from Adelaide's bowlers.
After collapsing to 4-15, Natalie Sciver-Brunt and Sophie Devine steadied with a 47-run stand for the fifth wicket but they were only batters to reach double-figures.
Sciver-Brunt's dismissal for 32 from 30 deliveries triggered another slide of 6-42, including the wicket of Devine (30 from 34).
Adelaide's Darcie Brown was superb with 3-18 from four overs while Amanda-Jade Wellington (2-17) and Danielle Gibson (2-17) were also standouts.
In their run chase, the Strikers' batters were cruising at 1-50 in the seventh over with opener Katie Mack making 24 from 27 balls.
Adelaide then stumbled, losing 4-18 with Perth's Devine (3-20) claiming two wickets in three balls to leave the home side 5-68.
But Madeline Penna (31no from 23) and Wellington (10no from 12) produced an unbroken 38-run partnership to steer the Strikers to victory.
