South East Stars 151 for 9 (Chathli 28, Maqsood 4-23) beat Sunrisers 61 (Gregory 4-12, Franklin 3-18) by 91 runs
Legspinner Danielle Gregory starred with a triple-wicket maiden to demolish Sunrisers for just 64 as South East Stars triumphed by 91 runs at Radlett to go top of the table in the Rachael Heyhoe Flint Trophy.
Sunrisers looked well-placed to record a first victory against their local rivals in any format after restricting them to 151 for 9 from 29 overs in a rain-reduced game, with legspinner Abtaha Maqsood taking 4 for 23.
But the Stars bowlers rose to the challenge, with medium-pacer Phoebe Franklin taking a trio of early wickets to finish with 3 for 18 while Sophia Dunkley pulled off four outfield catches, two of them outstanding.
Gregory then claimed three wickets in an over, returning figures of 4 for 12 as the innings disintegrated and Sunrisers were dismissed in 17 overs for their second-lowest score in the tournament.
After morning showers, play finally got under way at 12.45pm, with Sunrisers inserting their visitors in overcast conditions and gaining an early reward when Dunkley's leg stump was sent flying by Kate Coppack.
It took Stars until the fifth over to register a boundary, courtesy of Bryony Smith's sweetly-struck on-drive, but they began to gather momentum as she and Kira Chathli capitalised on short bowling from Coppack and Eva Gray.
A downpour struck with Stars 37 for 1 in the eighth over - and, when play resumed an hour later, the visitors continued to make good progress despite the loss of Smith, caught in the deep off opposite number Kelly Castle.
Paige Scholfield, with two centuries already to her name in this year's tournament, thrashed Gray for the first six of the game and followed it up with another maximum off Mady Villiers as she raced to 27 from 25 balls.
But the pendulum swung towards Sunrisers as Villiers had Chathli caught at midwicket for 28 and the innings never recovered after Maqsood's flight trapped Scholfield in front in the next over.
Smart glovework behind the stumps by Amara Carr brought the spinner two more wickets, while Alice Davidson-Richards was bowled attempting to drive through the off side and Grace Scrivens' tidy spell of 1 for 15 from five overs helped to squeeze the Stars tail.
Although the target was raised by four runs to align with DLS, Sunrisers set out needing less than five and a half an over - but that assignment looked close to impossible once their top order had been blown away by Franklin.
Freya Davies, a model of accuracy during her opening spell, brought one in to bowl Scrivens before opening partner Lissy MacLeod slapped a wide delivery from Franklin into the hands of the cover fielder.
Leaping to her left at extra cover, Dunkley pulled off a magnificent grab to remove Villiers and, when a slower ball by Franklin deceived Saskia Horley, the fielder gobbled up a more straightforward chance.
Cordelia Griffith did her best to hold Sunrisers' innings together, hitting four boundaries in her knock of 27 from 29 until she fell victim to another impressive catch by Dunkley, running back from mid-off to take the ball over her shoulder.
Gregory then collected three wickets in six deliveries, including a return catch to dismiss former team-mate Gray for a duck and although Carr and Coppack stemmed the bleeding with a stand of 20 for the ninth wicket, the damage had long since been done.
