Injury-hit Lancashire, who began the Twenty20 Cup as favourites, suffered their second defeat in three games as they went down by six wickets to Durham at Chester-le-Street.
Mal Loye was their latest casualty - pulling out following a back spasm - and with Dominic Cork (thigh) and Kyle Hogg (back) both missing the only regulars in their attack were Tom Smith and Gary Keedy.
But they still ensured that a crowd of 6,500 were kept on tenterhooks as Durham needed an unbeaten 56 off 32 balls by skipper Dale Benkenstein to see them past Lancashire's 135 for nine with four balls to spare.
After heavy away defeats in their first two Twenty20 matches, Durham had pegged back Lancashire following a runaway start, in which Simon Marshall thrashed 47 off 25 balls, including a six and eight fours.
It was 77 for one in the ninth over when he was sent back at the non-striker's end and beaten by Gareth Breese's direct hit from mid-wicket, which changed the game.
Tight bowling by left-arm spinner Graeme Bridge, who took two for 16 in four overs, kept a tight rein on the Lancashire youngsters and there were two more run outs with skipper Mark Chilton declining optimistic calls from his partners.
Durham were struggling at 29 for three after seven overs before Benkenstein put on 51 in six overs with Phil Mustard, who was caught at deep mid-wicket for 38.
With Gary Pratt joining his captain and Nathan Astle continuing to bowl tightly, the run rate dropped and 41 were needed off four overs when the captain smashed successive balls from leg-spinner Marshall over long on.
A single followed then Pratt drove a lovely four through extra cover as 19 came off the over. A good final over from Astle made the target 15 off two.
Benkenstein drove his fourth six over long on, off Steven Croft, and with 14 coming off the over only one was needed off the last, bowled by Tom Smith.
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