Thunder 250 for 8, with standout performances from Smale (76 runs) and Morris (54 runs), secured a commanding victory over South East Stars who managed to score 130 runs, with Chathli top-scoring at 54. The match ended with Thunder triumphing by a significant margin of 120 runs, with Cross leading the bowling attack with figures of 6-40.
England's Kate Cross took List A best figures of 6 for 40 as Thunder beat South East Stars by 120 runs in the Rachael Heyhoe Flint Trophy at Beckenham.
Batting first, Thunder made 250 for 8 from their 50 overs, Seren Smale top-scoring with 76 and Fi Morris making 54. Ryana MacDonald-Gay was the Stars' most potent bowler with three for 42 and she also claimed a run out, while Kalea Moore took 2 for 49.
Cross, however, did the damage by claiming the key wickets of Bryony Smith and Alice Davidson-Richards in successive balls. Despite a batting 54 from Kira Chathli Stars never really looked like chasing down the target and they were all out for 130 from 36.4 overs.
Thunder won the toss and chose to bat on a slow Beckenham track, putting on 53 for the opening wicket before Moore bowled Alice Clark for 23 in the 15th over.
MacDonald-Gay bowled Emma Lamb for 24 in the next over, but Smale and Morris shifted the momentum with a 96-run stand that was only broken when the latter chipped a Moore full toss to Paige Scholfield at cover.
MacDonald-Gay nearly had Smale for 43 in the next over but Chathli couldn't hang on to an inside edge and she was joined by Ellie Threlkeld, who made 33 before she was cleaned up by MacDonald-Gay. At that point the Thunder were on 205 for 4 with seven overs left but they lost wickets too frequently to mount a serious charge during the death overs.
MacDonald-Gay bowled Naomi Dattani for 14 and then ran out Danielle Collins for 1 as she chased a non-existent single, before Smale was smartly run out by Phoebe Franklin going for a second.
It was impossible to say who were favourites at halfway but Scholfield was unable to bat in her usual slot due to an injury and the odds tilted further in the visitors' favour when Cross intervened.
Stars skipper Smith went for just 12, caught at extra cover by Clark and Cross's next delivery bowled Davidson-Richards off the inside edge for a golden duck. Chathli survived the hat-trick ball at the start of the next over and was then dropped off the sixth ball by Dattani when she was on 2.
Makeshift opener Chloe Hill made a useful 18 in a partnership of 45 for the third wicket until Sophie Morris had her caught by Clark. Moore was bowled by Dattani for 6 and when Aylish Cranstone was lbw to Fi Morris for 9 Stars' hopes looked thin.
They looked thinner still when the same bowler had Franklin caught for 2 at cover by Cross and wafer-thin when Cross returned at the City End to get Chathli caught at long-on by Fi Morris.
In her next over Cross had MacDonald-Gay caught in the deep by Fi Morris for 13 and although Scholfield came in at No. 10, she was batting in visible discomfort and lasted just two balls before chipping Cross to Dattani for 1. An emphatic win was concluded when Cross bowled Dani Gregory for a duck.