Thunder 206 for 9 (Ecclestone 60*, Threlkeld 52, Munro 3-32) beat Lightning 146 (S Bryce 52) by four runs (DLS)
England spinner Sophie Ecclestone offered a glimpse of her ability with the bat as Thunder launched their Rachael Heyhoe Flint Trophy campaign with a four-run win over Lightning in a rain-affected match at Trent Bridge, smashing an unbeaten 60 off 61 balls.
The 21-year-old, who tops the women's T20I rankings as a bowler but rarely bats above nine in international cricket, hit six fours and two sixes, plundering 21 runs in the last over of the Thunder innings as they racked up a challenging 206 for 9 from their 50 overs.
Lightning's hopes of overhauling that total were dealt a major blow when their England opener Tammy Beaumont perished for just two. Scotland's Sarah Bryce hit nine fours in her 52 but once she had succumbed to Ecclestone's bowling the home side's chances always looked slim.
After 14 overs were lost to rain, a revised target of 151 left Lightning needing 32 off five overs once play resumed, but the combined experience of Ecclestone, England team-mate Kate Cross and World Cup winner Alex Hartley enabled Thunder to prevail in a tight finish.
Teenager Sophie Munro - who turns 19 on Monday - was the pick of the Lightning bowlers, the right-arm seamer taking 3 for 32, including two wickets in her opening three overs with the new ball.
However, a stand of 82 for the fourth wicket between wicketkeeper Ellie Threlkeld and allrounder Nat Brown rescued Thunder after a wobbly start and Ecclestone's big hitting ensured that their hard work was made to count - although some spirited hitting by Abbey Freeborn and Lucy Higham set up a close finish after the rain.
Lightning made good early inroads after Thunder had chosen to bat first on a bright morning, Munro striking with her third delivery for the Loughborough-based home side as Laura Marshall's miscued pull went straight to Beaumont at mid-wicket.
The right-arm seamer, who took 20 wickets for Nottinghamshire in county cricket last summer, was added to the England women's training squad during the winter. She picked up a second scalp in her third over, dismissing Emma Lamb in a similar fashion as Beaumont pouched another straightforward catch.
Thunder were 30 for two after 10 overs and immediately suffered another setback when Georgie Boyce was run out by Sophie Harman's fine throw from deep cover.
However, Threlkeld and Brown patiently brought Thunder back into contention, Threlkeld punishing England spinner Kirstie Gordon with a series of boundaries before Brown was run out for 38 by Abbey Freeborn's throw from point.
Munro claimed her third success when Threlkeld, having completed a 76-ball fifty, gave Beaumont her third catch with another mishit pull, but though Gordon and fellow spinner Lucy Higham were able to get among the wickets as Thunder chased runs, crucially neither was able to dislodge Ecclestone, who finished with a flourish by striking Higham's offbreaks for six, four, four and six in the final over of the innings.
Sarah Bryce looked fluent from the outset as Lightning began their reply, striking Brown's medium pace for three consecutive boundaries, but Beaumont had managed only two singles when, squared up by Brown, she squirted an easy catch to Olivia Thomas at short extra cover.
Joined by older sister Kathryn, the Lightning captain, Sarah led the way in a stand of 52 for the second wicket to keep their side close to the required rate but Kathryn was run out for 17 when Sarah declined her call for a single. Soon afterwards, after completing her own half-century, the younger Bryce was bowled by Ecclestone off a bottom edge.
Beth Ellis having been leg before to Hannah Jones, Lightning were still 88 short of their target with 19 overs left when rain took the players off for almost an hour, after which the DLS calculation revised the requirement to 32 off 30 balls.
It gave Lightning a glimmer of a chance but Higham's leg-before dismissal to Hartley sparked the loss of four wickets in seven balls and though Nancy Harman picked up a couple of boundaries, Ecclestone had the last word by bowling her off the penultimate ball.
"It was just so nice to get out there and play some competitive cricket and I think it would have been a good game to watch if there were any spectators in the ground," Ecclestone said. "For me, it was great to be able to bat at No. 6 when it is normally No. 9 or No. 10 for England; great to have the opportunity to get some runs.
"We're seen a bit as the underdogs in this competition but we have some good young players and it is a chance to show what they are made of."