Vipers 261 for 8 (Adams 82, McCaughan 47, Hall 4-46) beat Northern Diamonds 258 for 5 (Armitage 106*) by three runs
Georgia Adams starred with bat and ball as the Southern Vipers defeated the Northern Diamonds by three runs in a pulsating finish to an entertaining Rachael Heyhoe Flint Trophy game at South Northumberland Cricket Club.
Adams made 82 as the Vipers set a challenging total of 261 for eight from their 50 overs but Diamonds skipper Hollie Armitage struck a fine century to take her side within a whisker of their target.
The result keeps the Vipers well in contention for a third-place finish - and the final play-off spot - while the Diamonds also remain the mix as the competition heads towards an exciting climax later this month.
Lauren Winfield-Hill and Sterre Kalis made an excellent start to the Diamonds run chase, posting 52 in the powerplay with Winfield-Hill hitting five boundaries to reach a run-a-ball 29 but fell lbw to Ava Lee from the penultimate ball of the tenth over.
Kalis struck the ball powerfully in making 37 before falling lbw to Adams, with the Diamonds 98 for two in the 19th over but Armitage took over the run-scoring mantle to reach a 59-ball half century that kept the Diamonds in the hunt, and she found good support from the middle order as the hosts continued to close in on their target.
Emma Marlow lent great support in a third-wicket partnership of 61 before she was brilliantly caught and bowled by Nancy Harman for 20 leaving the Diamonds needing 103 off 100 balls.
Rebecca Duckworth helped Armitage add 44 for the fourth wicket but pulled Alice Monaghan to Harman at deep midwicket for 23 with need 59 off 52 balls.
Leah Dobson chipped in with a valuable 20 in a 51-run partnership with Armitage who batted superbly to reach her second Women's List A century from 101 balls including 11 fours.
The Vipers hung on, taking key wickets at crucial times, to leave the match evenly poised with 8 runs required from the final over.
And Georgia Elwiss clinched the victory with six excellent deliveries, bowling Dobson off the second and only conceding five singles with Armitage left unbeaten on 106.
The Diamonds made an early breakthrough after Adams had won the toss when Lizzie Scott produced a great delivery that nipped back to bowl Abi Norgrove for 6 and have the Vipers on 18 for one in the fifth over.
The visitors responded in positive fashion with Ella McCaughan and Adams compiling an excellent 109-run partnership across 24 overs that formed the bedrock of the Vipers innings.
McCaughan drove nicely either side of the wicket to move along steadily alongside her skipper before offering a return catch from a strong drive back to Grace Hall after making 47.
Adams was quickly into her stride striking two boundaries from her first seven balls faced, and regularly punished anything short or wide. Off spinner Katie Levick was driven for a straight six to add to the eleven fours struck in a classy innings of 82 off 91 balls.
It took an excellent yorker from Phoebe Turner to end Adams' innings when she looked well-set and leave the Vipers on 169 for three in the 37th over, but some excellent contributions from the middle and lower order saw a further 92 runs added from the final 81 deliveries.
Elwiss made 22 before edging an attempted cut off Hall to wicketkeeper Winfield-Hill while Emily Windsor kept the visitors' momentum going with a well-constructed 39 off 38 balls during the closing overs and Rhianna Southby contributed an unbeaten 15 off 6 balls.
The Diamonds attack - who lost Jessica Woolston to injury after the seamer had only completed five overs - bowled with commendable determination on a swelteringly hot day and were rewarded with late wickets as the Vipers finished on 261 for eight, with Hall taking four for 46 and Scott three for 33.
That total looked slightly under par and the Diamonds came so close to chasing it down.