Sunrisers 212-7 (Grewcock 56, Miller 47*, Knott 3-35) beat Southern Vipers 211 for 9 (Elwiss 53, Hancock 3-45) by three wickets

Sunrisers' Flo Miller smashed an unbeaten 47 from 59 balls to secure victory in a see-saw game against Southern Vipers at Radlett and take her side back to the top of the Rachael Heyhoe Flint Trophy table.

Vipers, the defending champions, looked clear favourites after reducing the home side to 138 for 6 in pursuit of their 212 target, with off-spinner Charli Knott taking t3 for 35. But Miller, 20, shared a seventh-wicket stand of 60 from 71 with Jo Gardner and kept her cool to score the winning run, securing Sunrisers' fourth win of the tournament with three balls to spare.

Jodi Grewcock top-scored for the home side with 56 from as many balls, while Sunrisers seamer Nic Hancock (three for 45) took her tally of wickets in the competition to 14 as the visitors posted 211 for 9, built around a Georgia Elwiss knock of 53 from 63.

Sunrisers, unchanged from last weekend's defeat to South East Stars, also stuck with their preferred game plan of bowling first after winning the toss - and carried it out sufficiently to ensure the visitors' innings never gained traction.

Kate Coppack (2 for 33) was consistent in the powerplay, gaining the initial breakthrough when she trapped Ella McCaughan lbw before spin duo Grewcock and Mady Villiers stifled the scoring rate.

Villiers dismissed the dangerous Knott, who drove her into the hands of midwicket and Abi Norgrove, having compiled a patient 35, fell to Coppack in identical fashion before Elwiss and Georgia Adams (42 from 64) began to make progress.

But Hancock made an instant impact with her second spell, bamboozling the Vipers skipper with a slower ball that hit the top of off stump and varying her pace again later in the same over to remove Emily Windsor.

Elwiss held the innings together, picking out gaps in the field and surviving after Gardner spilled a routine catch at deep midwicket off Amu Surenkumar to post her first half-century of the tournament.

She was dropped again in the deep by Miller, who recovered to dispatch an accurate throw and complete the first of two run-outs in the final over as Vipers slithered towards the finish line.

However, the home side also struggled at the start of their reply as Freya Davies (1 for 30) delivered two early maidens and Adams and Knott tied the opening pair down at the other end.

That pressure told as Sunrisers lost two wickets to run-outs in the space of three balls, with Scrivens' attempt at a second run doomed by Nancy Harman's pinpoint throw and Cordelia Griffith well short after Norgrove pounced on Amara Carr's sweep to backward square.

Yet instead of triggering greater caution, that double blow seemed to galvanise Sunrisers as Grewcock displayed intent and kept the scoreboard moving along as she and Carr (42 from 94) dragged the required rate below five an over.

Knott's return proved critical, breaking the partnership of 78 when Carr played on and Villiers holed out to deep midwicket before Surenkumar and Grewcock both fell to leave Sunrisers 138 for 6 - but Miller and Gardner kept their side in contention, bringing the target down to 18 from as many balls.

Although Gardner was caught at mid-off, Miller steered Mary Taylor to the deep third boundary and Hancock smashed four more to settle Sunrisers' nerves before her partner closed out the win.