Durham 187 for 8 beat Nottinghamshire 154 for 8 by 33 runs
Northern group leaders Nottinghamshire suffered their first defeat in this season's Friends Life t20 competition when they lost by 33 runs at Chester-le-Street.
Chasing Durham's 187 for 8, the Outlaws reached 105 for 1 before losing two wickets to successive balls in the 12th over and the mounting pressure saw them slump to 128 for 6.
They finished on 154 for 8 with seamer Chris Rushworth taking two wickets in the final over to finish with 3 for 20 in four overs. There were two wickets each for spinners Ian Blackwell and Gareth Breese, while Paul Collingwood held two catches and ran out Riki Wessels.
Durham were also guilty of losing their way with the bat, but not until they had sped to 145 for two in 13 overs with Phil Mustard making 75 off 41 balls with 11 fours and two sixes. The score had reached 44 in the fourth over when Mustard cut Darren Pattinson to point and declined Gordon Muchall's call for a run. Muchall kept on coming and was run out for 11.
Durham had 67 on the board after the six-over powerplay and Mustard reached 50 off 28 balls by driving Andy Carter over mid-off for his eighth four in the eighth over. Mustard departed in the 12th over when he drove at a slower ball wide of off stump from medium pacer Steven Mullaney and was stumped by Chris Read.
Collingwood made only 8 before going down the track and having his stumps splattered by Carter. The runs were really drying up when South African David Miller declined Blackwell's call for a leg bye and Blackwell was run out for 43, made off 27 balls.
Dale Benkenstein became the third run out victim when he drove to mid-off and had no chance of beating Pattinson's direct hit. After making 19 off 17 balls Miller flipped an easy catch to short fine-leg off Pattinson, who also had Breese lbw and Liam Plunkett caught at deep square leg off the penultimate ball to finish with 3 for 31.
When Graham Onions bowled a poor second over, in which he was punished for dropping short by conceding 20 runs, the visitors looked to be on their way to their fifth win from six games. Adam Voges and Wessels had put on 68 for the second wicket when Voges fell for 46, clipping Blackwell to Collingwood at mid-wicket.
When David Hussey tried to get off the mark off the next ball he succeeded only in running out Wessels for 32 and the rest perished to a series of frantic strokes as the Outlaws fell 33 runs short.