Southern Vipers 230 for 6 (Windsor 47*, Adams 41) beat South East Stars 227 (Brewer 79, Bell 4-36) by 4 wickets
Lauren Bell's return to Southern Vipers from the England training bubble proved a memorable one, as she claimed 4 for 36 to set up a four-wicket victory against South East Stars at The Kia Oval, leaving Vipers undefeated in the group stages of the Rachael Heyhoe Flint Trophy and headed to next weekend's final.
Stars' Chloe Brewer, making only her second appearance in the competition, hit an impressive 79 at the top of the order, but Stars squandered their solid start, collapsing from 145 for 3 to 227 all out in 48.3 overs.
In what turned into a nail-biting run chase, it was the 72-run sixth-wicket partnership between Carla Rudd, who made 35, and Emily Windsor, with an unbeaten 47, which ultimately proved decisive for Vipers, Windsor hitting the winning runs in the 48th over with 16 balls to spare.
Vipers had initially looked to be going steady at 70 for 1 after 15 overs, before back-to-back dismissals in the 16th and 17th gave them a wobble - captain Georgia Adams caught and bowled by Hannah Jones for 41, while Maia Bouchier fell lbw to leg-spinner Danielle Gregory for 10.
With their captain and the leading competition run-scorer back in the dugout, Charlie Dean and Paige Scholfield began the necessary rescue work but could not see the job through, as Gregory and Jones struck in tandem again in their consecutive second spells, leaving Vipers five down.
But Vipers' experienced middle order eventually proved their mettle, ensuring they maintained their winning momentum going into the Trophy final
Stars' batting was expected to be buoyed in the last round by the return of England players Bryony Smith and Alice Davidson-Richards, but both fell for single figures - Smith the first wicket to fall, driving straight into the hands of Bouchier at extra cover in the fourth over.
Instead it was two teenagers who did the heavy lifting for Stars, with 18-year-old Brewer well supported by 16-year-old Alice Capsey, as the pair shared a 77-run partnership for the third wicket. Coming together in the 12th over after Aylish Cranstone was lbw to Charlotte Taylor attempting a sweep, they remained at the crease until the 30th, moving the total along from 52 for 2 to 129 for 3.
Both eventually fell in near-identical fashion, sending the ball up into the safe hands of Bouchier - the 21-year-old snaffling a total of four catches in her signature position at extra cover to leave her with a tally of 10 across the group stages, the highest of anyone in the competition.
Bell's reintroduction in the 33rd over helped further dent the Stars' innings, with her victims including both top-scorer Brewer and Stars' captain Tash Farrant, bowled by a brilliant yorker.
Grace Gibbs attempted to salvage things with a rapid 19-ball 30 at the back end to take Stars past 200, including two beautifully struck sixes against the off-spin of Adams. However, two smart run-outs from Scholfield at midwicket finished the job, with Stars bowled out in the 49th - nine balls of their innings going unused.