Worcestershire 159 for 5 (Mitchell 59, Kohler-Cadmore 53*) beat Durham 156 for 7 (Mustard 43, Muchall 41*, Ajmal 3-16) by 3 runs
Saeed Ajmal pulled off perhaps his most encouraging bowling display since the ruling that his action was illegal threatened to end his career as Durham Jets, seemingly well placed for victory, found their lead disappearing in the NatWest T20 Blast North Division.
It looked as though Durham would make light work of their target of 160, but the early dismissal of Mark Stoneman and a middle order collapse ensured that Worcestershire Rapids' 159-5 was sufficient to take the points, Durham losing by three runs.
Ajmal, who returned 3 for 16, was the most successful bowler on view, including the Durham captain Phil Mustard among his wickets before stifling the tail in a manner that left Mustard boiling with frustration.
Warwickshire have drawn level with Durham at the top of North Group, and they have three games in hand - a position similar to many in the chasing pack.
Daryl Mitchell, Durham's captain, said: "Credit to the lads to show some spirit to fight back, helped by a little bit of magic from Saeed Ajmal. The wizard is back and that was a fantastic spell from him."
Mustard said: "It's a very disappointing result. We were in pole position. We needed 54 with seven wickets in hand and for a team of our stature we should never get beat from that position. We should have never taken it down to the last two overs - that's the biggest disappointment in the dressing room."
Ajmal returned to begin his third spell for Worcestershire against Northants the previous week, without success, but, having remodelled his action, faces the challenge of regaining his potency as many pundits believe that his Pakistan career is over.
Worcestershire remain adamant that his career is far from spent and he can conjure up reminders of his success of last season when he helped them to promotion in the Championship as well as the Blast quarter-finals.
Winning the toss, the Rapids' innings was held together by Mitchell, who led the way for the visitors with 56 from 49 balls, while Tom Kohler-Cadmore carried his bat for 53.
England all-rounder Moeen Ali opened up for Worcestershire and looked in good nick until being caught by Keaton Jennings at the legside boundary in the sixth over off Chris Rushworth. Ali's innings included three fours and a six, after he had survived an appeal for lbw in the first over. Richie Oliver followed Ali in the seventh over, caught behind at short third man by Rushworth off Paul Collingwood's fifth ball.
But Worcestershire settled down with the introduction of Kohler-Cadmore, alongside Mitchell the partnership yielded 76 for the third wicket, easing to 74 for 2 at the halfway mark.
However, Durham tightened up and Mitchell was dismissed in the 17th over courtesy of Usman Arshad, Calum MacLeod taking the catch, before the Durham bowler trapped Ross Whiteley in the same over for a duck.
Colin Munro was let down heavily by Kohler-Cadmore after his partner dropped his bat in between the wickets in allowing the batsman to be run out in the 19th, before Kohler-Cadmore brought up his 50 in the final over.
Durham's reply got off to a perfect start as Mark Stoneman eased the hosts to 40 without loss after three overs, notching up a magnificent 18 runs from one Ed Barnard over.
But the Durham opener - after Ajmal bowled a maiden- was dismissed off the first ball of the fifth over off Jack Shantry when he toe-ended a lofty drive, caught at mid-off by Kohler-Cadmore.
Mitchell proved to be a thorn in the hosts' side with two wickets in two balls, dismissing MacLeod for 13 and sending Collingwood back to the dugouts for a duck as Durham progressed to 87 for 3 at the halfway mark.
Phil Mustard gave Durham a fighting chance with his 43, which included two fours and two sixes, but was caught at long point in the 14th over after miscuing a reverse sweep.
Ryan Pringle followed after he was stumped by Ben Cox after he came down the wicket from an Ajmal delivery but fluffed his lines as Durham teetered on 112 for 5.
Hastings was run out for four in the 16th over before Ross Whiteley caught Usman Arshad at the boundary off Ajmal's delivery in the 18th.
Durham finally found the boundary from their last two balls courtesy of Gordon Muchall, but it was too little, too late as the hosts fell short.