A costly penultimate over from Liam Plunkett handed his former county Durham Dynamos a first Friends Life t20 win at the second attempt against Yorkshire Vikings at Scarborough.
Durham looked down and out needing 82 runs off eight overs in their pursuit of 147, and even more so when they lost top-scorer Phil Mustard, off Plunkett, for 59 to leave the score at 110 for five after 16.5 overs.
But Gordon Muchall's 44 not out from 27 deliveries was crucial, including getting the lion's share of 16 off Plunkett in the 19th to take the equation from 25 off two overs to nine off the last.
Michael Richardson hit the winning runs from the penultimate ball of the match to seal a four-wicket win for Durham, who opened their campaign with a North Group loss to Lancashire on Friday.
Last season's finalists Yorkshire have now lost their first two ahead of Friday's Roses clash at Headingley.
It was rough justice for Plunkett, who had contributed significantly with bat and ball.
The all-rounder hit a late 30 off 16 balls to boost the Vikings' total to 146 for seven, which saw 39 runs come off the last three overs.
He then had Mustard caught at deep point to end a fifth-wicket stand of 45 with Muchall.
But Plunkett conceded 14 runs off the first four balls of the 19th over, including three boundaries to Muchall, and let the contest slip.
Jack Brooks had got Yorkshire off to an excellent start in their defence with 2-13 from four overs on the spin with the new ball. The ex-Northamptonshire man had taken four wickets against Derbyshire on Friday.
He had Mark Stoneman caught behind after just five balls and Scott Borthwick taken in the deep pulling.
Durham's fledgling off-spinner Ryan Pringle mirrored Brooks' figures as the Vikings lost six wickets for 52 in 10 overs having been 51 without loss after they were inserted.
Durham countered the loss of captain Paul Collingwood, who won the toss and invited the hosts to bat, due to a right thumb injury having taken a sharp caught-and-bowled chance to get rid of Dan Hodgson.
Four of the seven Yorkshire batsmen were bowled as Collingwood, Will Smith, Mark Wood and Ben Stokes also struck before Plunkett favoured the straight boundary at either end of the ground to strike two fours and two sixes.