Top side Northern Districts and second-placed Kensington were outplayed in Saturday’s semi-finals, crashing out of the title race on their home turf.
Sturt, which last won the main title in 2010-11, restricted Northern Districts to 9/158 and then reached its target with three overs and four wickets to spare at Salisbury Oval.
Northern Districts collapsed from 1/52 to 7/88 after opener Tegan McPharlin made 33 before the side steadied through Tabatha Saville (37 not out) and tailender Sophie Roberts (17).
Stacey Oates claimed 4/30, Amelia Rault took 2/31 and spinner Alex Price finished with 1/12 from 10 overs.
Sturt’s successful chase was launched by Annie O’Neil (37) and Eliza Bartlett (34) and then controlled by teenager Emma de Broughe, who made 38.
Southern District booked a spot in its first ever women’s grand final with a solid all-round performance completed by the bowlers.
The Stringrays ripped through Kensington, Vanuatu’s Selina Solman taking 5/25 from her 10 overs and Jess O’Reilly claiming 2/15 as the Browns collapsed to 9/44 chasing 170 to win.
Openers Eliza Doddridge and Rachel Church fell cheaply but captain Sarah Lowe (16) and Shania McKinnon (11) showed some resistance before the Browns lost 7/19. They were eventually dismissed for 70.
Earlier, Hannah Sampson (51 off 68 balls) took advantage of a solid start from O’Reilly (25) and Kelly Armstrong (27) and combined with Kylie Rattray (23 off 20) to push Southern District’s total to 169.
Katelyn Pope was Kensington’s most successful bowler, snaring 4/19 off eight overs, and Lowe took 2/17.
The grand final will be played at Karen Rolton Oval on Sunday.