An enthralling game which swung back and forth throughout saw the Diamonds well placed at 74 for one in the 15th over of their chase, only to slip to 96 for six in the 23rd as brilliant off-spinner Taylor struck the decisive blows.
She had opener Hollie Armitage (26) caught at backward point, Alex MacDonald out hit wicket, Jenny Gunn trapped lbw and Bess Heath caught at deep mid-wicket.
The Diamonds were later bowled out for 193 inside 43 overs, with 26-year-old Taylor also trapping Beth Langston lbw and getting Netherlands international Sterre Kalis caught at mid-on for 55 on the way to a fabulous six for 34 from 10 overs - the best haul from any bowler in the competition.
Taylor, who claimed the player of the match award, said: “It was a great final on a great ground, and it could have gone either way. I’m sure it made for a brilliant game for everyone watching on the telly.
“That’s the best I’ve ever bowled. I couldn’t have asked for anything better.
“I’m proving to myself week in and week out that I can play at this level.
“The Diamonds started off very strongly in their chase after we got a score which we thought was competitive.
“We had our sights on 250 at the start, but we pegged it back to 230.
“Armitage, Winfield-Hill and Kalis got them off to a good start, but we took wickets at key times, and I’m so happy I was able to contribute.
“Lots of people wouldn’t have seen me play too much cricket, and I think that works to my advantage, especially with my bowling.
“This team is so young. Myself, Georgia (Adams) and Carla (Rudd), we’re some of the oldest at 26. And some of these girls are 16, even 15. So for us to win seven games out of seven with such a young side, it’s really impressive and bodes well for the future.
“I work in aerospace, selling plane parts I suppose you could say.”
Vipers’ captain Georgia Adams continued her stunning form with 80 off 102 balls, including eleven fours, at the top of the order as she underpinned 231 all out and moved to 500 competition runs in the process.
She shared a century opening partnership with Ella McCaughan (35) having been inserted, only for the Diamonds to drag things back impressively as leg-spinners Katie Levick and Hollie Armitage shared five wickets.
After Adams and McCaughan shared 100 inside 24 overs, their side’s fourth century opening stand in seven games, the South Coast side were in a dominant position at 150 for one in the 32nd over.
Adams was particularly strong square of the wicket, reaching 50 for the fourth time in this competition off 68 balls.
Maia Bouchier, however, looked more fluent at the crease and was punishing through the covers and over the top on the way to 28.
With herself and Adams together - they shared 50 inside eight overs after McCaughan had feathered left-arm spinner Linsey Smith behind - a total nearing 300 was not unrealistic on a pacy and true surface with a fast outfield.
But things changed in a flash. Captain Lauren Winfield-Hill, back from England’s T20 bubble, brought Armitage into the attack, and she struck first ball with a long hop which Bouchier pulled head high to mid-on, leaving the score at 150 for two in the 32nd.
Almost 12 overs later, the Vipers were 191 for eight, with Armitage striking again added to three wickets for Levick, who trapped Charlie Dean and Carla Rudd lbw and removed Adams caught at deep mid-wicket.
Levick’s first two overs had cost her 19, only to finish with three for 49 from eight.
Miserly former England seamers Langston and Jenny Gunn both contributed significantly in dragging things back and finished with a wicket apiece.
However, there was to be a late twist as the Vipers were boosted by an industrious 37 off 48 balls from Emily Windsor to ensure they went beyond 230.
The Diamonds made a solid start to their reply before Winfield-Hill (20) chipped seamer Bouchier’s second ball to cover - 36 for one in the eighth over.
Armitage then launched the game’s only six - over mid-wicket off the seam of Paige Scholfield in the 12th over.
But the Diamonds were about to lose their way, as the Vipers had done earlier. Unfortunately for them, this was to be far more damaging.
Armitage, Campbell and MacDonald, the latter hit wicket playing back at a quicker ball from Taylor, all fell to the first ball of the 15th, 16th and 17th overs before Gunn and Heath followed as the Diamonds slipped to six down still needing 136 more to win.
Another off-spinner Charlie Dean then trapped Smith lbw as the score fell to 110 for seven after 26.
Kalis, who batted at three and watched the collapse from the other end, tried in vain to rescue things with a polished 75-ball knock.
She shared 49 for the eighth wicket with Langston, who fell for 21 in the 35th over to provide Taylor with her fifth wicket.
Kalis then became her sixth shortly after reaching 50 in the 37th, and Taylor finishes with a competition high 15 wickets in five appearances.
Skipper Adams wrapped up the win by getting Phoebe Graham caught at mid-wicket in the 43rd over, sparking jubilant celebrations.
Northern Diamonds captain Lauren Winfield-Hill said: “They started well with that big partnership up top before we clawed it back in the middle and kept them to a score.
“At one stage we thought it was a 260 pitch, but in the end they probably got 20 or 30 too many with people down the order chipping in. That proved to be the difference.
“We didn’t bat very well. There were a lot of soft dismissals. A lot of people got themselves out rather than being got out.
“But we’ll learn from that. We just need to be playing in these finals and find a way to win.
“It was a great wicket - a hybrid wicket - so we knew there was going to be some pace in it. But there were a few dismissals, including mine, which made you think there was a two-paced nature to it. I certainly don’t think the pitch had any part in the cluster of wickets which fell in both innings.”