Lancashire opener Gaby Lewis scored a superb 141 not out from 143 balls as her team became the inaugural Metro Bank Women's One Day Cup champions and inflicted a third defeat on a Hampshire side in a final in nine days.
Lewis and Seren Smale (72 off 85) underpinned a successful chase of 289 at the Utilita Bowl in Southampton as Lancashire won by six wickets with nine balls to spare.
Hampshire had earlier made 288-6 with Georgia Adams (77) and Maia Bouchier (66) hitting half-centuries and Lancashire seamer Grace Potts bagging 3-47.
Hampshire's men had been beaten in the , after losing to Somerset in the Men's Vitality Blast showpiece the previous weekend.
Adams' side finished top of the table in the Women's One Day Cup group stage with nine wins and a sole defeat, beating Lancashire by eight wickets in Southport during round three before the teams' clash at Arundel in the final round was washed out.
On Sunday, Hampshire were unable to kick on in the final overs of their innings after captain Adams was dismissed in the 46th, losing a cluster of late wickets.
They were buoyed by the early run out of Alice Clarke (3) in the chase but Lewis and Smale proceeded to add 144 for Lancashire before Lewis shared stands of 61 and 46 with Ellie Threlkeld (32) and Ailsa Lister (17no) respectively.
The victory secured Lancashire a second title of the season after the Vitality T20 Women's County Cup.
Surrey won the Women's Vitality Blast, while Northern Superchargers triumphed in the women's competition in The Hundred.
