The Invincibles triumphed by 48 runs, with Brave slumping to 14 for six and being bowled out for 73, the lowest score of the competition, as they chased 122 for victory.
Marizanne Kapp, who starred with bat and ball in Friday’s eliminator victory over Birmingham Phoenix, took centre stage again, striking 26 off 14 balls before taking four wickets for nine runs.
Anya Shrubsole’s Brave had gone into the final as favourites after topping the league with seven wins and just one defeat, but the loss of early wickets proved too much to come back from. It was an occasion to forget for England internationals Danni Wyatt and Sophia Dunkley, with South African Kapp removing both for ducks.
Opener Gaby Lewis and Australian Amanda-Jade Wellington also failed to get off the mark as Brave found themselves six down after just 36 balls. Kapp stuck with her fourth ball as Wyatt edged behind to Sarah Bryce, with Dunkley following her international team-mate just two balls later, caught by captain Dane Van Niekerk.
The 31-year-old had a third wicket inside the opening 10 balls as Lewis top-edged to Alice Capsey, leaving Brave two for three. Maia Bouchier was dropped off Tash Farrant on four but was only able to add three more runs before being run out by a direct hit from Fran Wilson.
Wellington then fell to Shabnim Ismail and Shrubsole to Capsey for one as Brave were left needing 101 from the final 50 balls, with just four wickets in hand. Any faint hopes all but disappeared when Stefanie Taylor was stumped on 18, but Fi Morris and Tara Norris put on 33 for the eighth wicket, the former top-scoring with 23.
But fittingly it was Kapp who wrapped up the innings with the wicket of Lauren Bell with two balls left. The Invincibles had earlier made 121 for six, Van Niekerk (26) and Wilson (25), who survived being dropped on 17 by Dunkley on the boundary, compiling a partnership of 56 following the early loss of Georgia Adams.
Kapp hit four boundaries in her quickfire 26 before falling to Morris and Capsey struck 18 from 12 as the Invincibles set a target which proved far too tough for Brave to match