The Blaze 120 for 7 (Beaumont 38, Ecclestone 2-18) beat Thunder 117 for 6 (Heap 26, Ballinger 2-23) by three wickets
Beaumont was one of six Ashes contenders featuring in a low-scoring affair played after Lancashire men had beaten Leicestershire in the Vitality Blast, with star duo Nat Sciver-Brunt and Sophie Ecclestone going head to head.
Both impressed as Thunder made 117 for 6 and failed to defend it. Ecclestone returned 2 for 18 from four overs of left-arm spin, while Sciver-Brunt's seamers accounted for 1 for 23 from four before adding 21 off 14 balls in the chase.
But Beaumont usurped them both, striking the ball better than anyone with eight fours and a flicked six to ensure the Blaze continued their unbeaten start to the summer.
The Blaze survived a late wobble from 88 for 2 to 98 for 6 to win inside 16 overs and have now won five of seven matches across the Charlotte Edwards Cup and the Rachael Heyhoe Flint Trophy in their first season based at Trent Bridge, including two from two in this T20 competition.
The East Midlands side have been rebranded from Lightning after three seasons based at Loughborough University.
For Thunder, their disappointing start to 2023 continues. They are winless in seven games across the two competitions, including a pair of T20 defeats.
Beaumont, Ecclestone, Kate Cross, Sarah Glenn, Emma Lamb and Sciver-Brunt were the England players on show.
Thunder failed to gain any significant momentum through an innings strangled by an on-point five-strong bowling attack. Left-arm seamer Grace Ballinger took the new ball and stood out with 2 for 23 from her four overs, while Sciver-Brunt, captain and spinner Kirstie Gordon, legspinner Glenn and South Africa seamer Nadine de Klerk all struck once.
Opener Libby Heap top-scored with 26 for Thunder, while captain Ellie Threlkeld and Cross both made 22.
Lancashire had promoted the day as Empower Play, with £1 from each of the 3,101 tickets sold across the day donated to women's and girls' participation initiatives in conjunction with the Lancashire Cricket Foundation.
Thunder were in trouble early when England opener Lamb chipped Gordon's left-arm spin to mid-off to fall for 2 four balls into the match before Ballinger bowled big-hitting West Indian Deandra Dottin for 9 as the score fell to 14 for 2 in the fourth over.
Heap, Threlkeld, Fi Morris with 18 and Cross were all busy in trying to advance Thunder's cause, but they slipped from 82 for 3 in the 15th over to 89 for 6 in the 18th to undermine hope of a challenging total.
Morris was bowled by Glenn, Heap was well caught at short third by ex-Thunder batter Georgie Boyce off Sciver-Brunt and Ecclestone was caught at short fine-leg for only three off Ballinger.
In the first over of the chase, Beaumont made her intentions clear by sweeping and lofting international colleague Ecclestone for back-to-back boundaries. Her flicked six over midwicket came off the seam of Tara Norris, while she hit three boundaries in the same area in dominating a 56-run opening stand with Marie Kelly.
The latter was bowled sweeping at Ecclestone for 16 in the sixth over before Beaumont was lbw sweeping at the offspin of Morris an over later - leaving the Blaze 56 for 2.
Sciver-Brunt, in at No. 3, then clubbed and carved three fours in as many balls off UAE international fast bowler Mahika Gaur to maintain Blaze's dominance.
Cross had Boyce (15) caught at point as the score fell to 88 for 3 in the 10th over, sparking a mini collapse to 98 for 6 after 12 which only delayed the inevitable. Sciver-Brunt miscued Norris to short midwicket before Ecclestone bowled de Klerk as part of that. Glenn later hit the winning runs and finished 17 not out.