The Blaze, missing their three England players but accustomed to managing without them, would have seen chasing 242 as well within their compass, although less so after matching their opponents in losing three wickets in their opening powerplay.
Mahika Gaur bowled Sarah Bryce with a full delivery for five before Cross removed Georgie Boyce, caught and bowled off a leading edge for 14, and Prendergast, who stepped across to be leg before for a second-ball duck, leaving The Blaze in peril at 37-3.
But just as Threlkeld and Lister rescued Lancashire, Elwiss joined Kathryn Bryce to turn their side’s innings around.
Yet though Bryce passed fifty for the seventh time this season from 64 balls, none of Threlkeld’s six bowlers conceded runs easily.
Bryce brought up her hundred, the fifth of her career in List-A cricket and a first in Blaze colours, from 121 balls as the partnership ticked over to 150.
But the big breakthrough for Lancashire came shortly afterwards as Elwiss, who had clocked up her fifth half-century of the season, was caught at backward point on the reverse sweep off Fi Morris, with 55 still needed off 52 balls.
The wicket opened up one end for the visitors and after Marie Kelly (five), Michaela Kirk (nought) and Lucy Higham (four) all went cheaply, The Blaze needed 33 from 18 balls
That came down to nine off the last over, but when Bryce holed out to mid-off off the second ball to give Potts her second wicket, their chance had gone.
