The Blaze 303 for 7 (Kelly 79, Prendergast 56) beat Warwickshire 302 for 5 (Pavely 128*) by three wickets
Charis Pavely underlined her explosive qualities with the bat by smashing a career-best unbeaten 128 off just 102 balls yet it was not enough to secure victory for Warwickshire after The Blaze smashed 105 off the final 10 overs to take the points in the Metro Bank One-Day Cup women's competition.
After opener Marie Kelly had laid the foundations with a List A career-best 79 and England skipper Nat Sciver-Brunt had contributed 47, it was a 30-ball 56 from Ireland international Orla Prendergast ultimately proved the match-winning knock. She led a partnership of 69 with Georgia Elwiss before Blaze skipper Kirstie Gordon added to the drama, taking advantage of a missed caught-and-bowled chance by Alexa Stonehouse to run the winning single with four balls to spare.
Pavely, the 21-year-old left-hander, whose potential has already earned her an £85,000 deal with London Spirit in this year's Hundred, hit 13 fours and five sixes, although she had luck on her side after being dropped twice just moments after passing fifty.
She shared an exhilarating 197-run partnership with Katie George, who passed her career-best mark of 80 and hit 13 fours but fell two runs short of a century.
Earlier, in a topsy-turvey first innings, The Blaze had looked in control with Warwickshire 64 for three in the 19th, having opted to bat first. But that solid start with the ball was undermined by a poor day in the field, with four catches put down at a cost of more than 100 runs.
Seamer Charley Phillips, the pick of The Blaze attack, removed Davina Perrin after she had been dropped on four, before Sciver-Brunt struck twice to dismiss Amu Surenkumar via a top edge and Meg Austin leg before.
Yet Pavely and George were unstoppable, albeit helped by some howlers in the field. Pavely reached 51 from 42 balls, twice clearing the ropes and hitting seven fours, only to be put down at mid-off on 52 off Prendergast and extra cover on 55 off Grace Ballinger, both straightforward chances.
She reached three figures from just 83 deliveries, raising her boundary tally to 11 fours and four sixes.
George, dropped on the boundary on 81, looked set to post her own maiden List A ton only to be caught behind on 98, looking to cut Ballinger.
In reply, The Blaze were 33 for one from 10 after losing opener Tammy Beaumont, reaching 103 for one after 25 before Pavely's left-arm spin trapped Bryce leg before for 38.
Kelly completed her second half-century of the season and with Sciver-Brunt starting to go through the gears, 176 from 20 looked within Blaze's compass.
Yet the balance shifted as Sciver-Brunt was dismissed for 47, bowled middle stump by up-and-coming England quick Issy Wong.
Warwickshire suffered a setback when seamer Em Arlott limped off with an injury but Kelly's fine innings ended with a catch at cover off Pavely in the 40th over with 108 still needed, and Pavely then held a fine catch on the boundary to remove Amy Jones.
Yet Prendergast, aided by Georgia Elwiss's 31 off 17, hauled back the initiative brilliantly. She departed to a steepling catch and Elwiss was taken on the rope but a poor final over by Wong kept The Blaze in the running and they did not squander the chance.
