Brisbane Heat are through to their fourth WBBL final after completing a nine-wicket win over Sydney Thunder.

Heat skipper Jess Jonassen sent the Thunder in at Brisbane's Allan Border Field and marshalled her bowlers to perfection as the visitors crashed to 7-69.

A record WBBL stand of 64 for the eighth wicket by Hannah Darlington (40 not out) and Taneale Peschel (24 not out) lifted the Thunder to 7-133 from their 20 overs.

But the Heat polished off the runs in 15.2 to set up a WBBL final showdown away against Melbourne Renegades at the MCG on Sunday.

India international Jemimah Rodrigues was dropped three times on her way to 43 off 30 deliveries before retiring hurt.

She combined with opener Georgia Redmayne (53 not out) to anchor the Heat's run chase.

Rodrigues had injured her left wrist in the field and had to retire in the 10th over.

She is likely to miss the final but Redmayne and Charli Knott (19 not out) at least showcased the Heat's batting depth.

Leg spinner Grace Parsons earlier took 3-10 in three classy overs to set up her side's sixth straight win.

She received her second official player-of-the-match award after earlier claiming 3-22 against Renegades.

Parsons snared the key wicket of Thunder skipper Phoebe Litchfield (15), who was brilliantly caught by Jonassen at mid-off as she leapt high and snaffled a well-hit drive above her head.

In the run chase, the Heat lost Grace Harris (7), stumped early after a wild heave, to give Sam Bates her 20th wicket of the season.

Redmayne and Rodrigues then ensured the hosts were able to cruise to victory.

AAP