Perth Scorchers have lost their fourth — and most important — game in a row, to be dumped from the WBBL in a home final on Wednesday night.

For a second time this season, the Scorchers were torched by Grace Harris. The Heat master blaster smoked 54 off 33 balls in her team’s 5-197 — the biggest total ever in a final.

In a WACA Ground final that fell in their lap, the Scorchers’ top-order capitulated again to fall 67 runs short.

It brings a premature end to a season where Perth sat on top in the final weeks and sends the Heat through to Saturday’s final against the Strikers at Adelaide Oval.

The Scorchers bowlers Harris pummelled in her record knock at North Sydney earlier this season were again watching balls sail past and over them.

She hit a boundary off Amy Edgar’s third ball of the game and back-to-back fours off Chloe Ainsworth in a powerplay over that went for 15. Sophie Devine wasn’t immune either, her third over went for 14.

By the end of the restrictions they had raced to 0-41 — and Harris had 32 of them.

Milking the spinners on a wicket harder and flatter than recent WACA offerings, Harris’ half-century came off just 26 balls and it took a rearing in-swinger from Nat Sciver-Brunt to dismiss her for 54.

Harris and opening partner Georgia Redmayne both used reviews on lbw calls, dismissed in consecutive overs.

Amelia Kerr rode her luck, dropped in a caught-and-bowled sitter by Edgar, before finding her at short fine-leg overs later for 31.

The Scorchers kept the power-surge to 15 before the wicket of Mignon Du Preez for 26 brought Laura Harris to the crease.

Harris exploded in the final overs. Even balls off the toe of her bat carried over the long-on boundary, but one that landed on the eastern bank over mid-wicket was far sweeter.

Her blistering 24 off 11 lifted their score to the ninth highest of all time.

Lauren Winfield-Hill’s 15-run cameo at the top held promise. She ramped the first ball and hit two boundaries in the first over, before chunking a ball to mid-on.

Chloe Piparo sliced a point to ball for six and after waiting 10 balls to see the strike, while Mooney struggled to get out of second gear in her 16-ball 18.

Devine and Nat Sciver-Brunt held the Scorchers’ tickets to Adelaide in their hands. Devine hit two boundaries with cute sweeps and Sciver-Brunt was the first Perth batter to effectively tick the strike over.

That ended in a bizarre moment where Devine skied a ball to wicket-keeper Redmayne but strolled out of her crease — rather than standing her ground — and was caught.

Sciver-Brunt and youngster Maddy Darke needed just over 12 an over past half-way before the English import’s Scorchers stint ended when she was struck on the pads and given out for 36.

Spinner Georgia Voll to 4-19 and was on a hat-trick twice as the Scorchers lost their final three wickets for 11..