Heather Knight hit a superb unbeaten 78 to help Western Storm win the final Kia Super League with a six-wicket success over Southern Vipers.
The 2017 winners pulled off a KSL final record chase of 173 with an over to spare at Hove as Storm captain Knight became the only player in the tournament's four-year history to pass 1,000 runs.
Vipers posted 172 for seven from their innings after winning the toss, with Knight's England team-mate Danni Wyatt contributing a brilliant 73.
Storm required 64 off eight overs after Fran Wilson and Sophie Luff departed in the 12th over but the big-hitting Deepti Sharma (39) gave Knight superb support in an unbroken stand of 71 from just 33 balls for the fifth wicket.
Victory for the Storm, their second title, capped an impressive campaign which saw them record nine wins and a single dead-rubber loss in the group stage.
Knight said: "I thought at the break we'd done well to drag it back to 172 because the way Danni Wyatt was batting at one stage, it looked like we'd be chasing 200.
"We've got terrific belief in our side from winning games in a lot of difficult situations over the last couple of years. We knew if we got a couple of partnerships and one person was in at the end that we could win.
"I was delighted we finished the job and gave the KSL the send-off it deserved. The Vipers played their part and I thought it was a great game."
Vipers captain Tammy Beaumont said: "I'm pretty gutted but all credit to Heather, who played brilliantly."
Our support over these last 4 years has been nothing short of remarkable and we'd like to thank everyone who has called themselves a Western Storm supporter ❤️#StormTroopers 🌪️ 🌪 pic.twitter.com/GnhOHXiLrN
— Western Storm 🏆🏆 (@WesternStormKSL) September 1, 2019
Earlier on Sunday, the Vipers reached their third Super League final by beating Loughborough Lightning by five wickets with an over to spare.
Chasing 144 for victory, Vipers were set up by an opening stand of 75 from just 39 balls by Suzie Bates and Wyatt.
Lightning, who were beaten in last year's final, had been bowled out for 143 in 19.5 overs after Bates finished their innings with three wickets from five balls in the final over.