Northants 162 for 4 (Duckett 72) beat Durham 161 for 7 (Burnham 53*, Collingwood 38) by six wickets
Ben Duckett's 72 helped champions Northamptonshire home by six wickets with four balls to spare in the repeat of last year's NatWest T20 Blast final against Durham at Chester-le-Street.
There was also a vital contribution for Northants from South African spinner Tabraiz Shamsi. While Durham were unable to find a late substitute for the injured Tom Latham, Shamsi has been brought in for three games until Sri Lankan Seekkuge Prasanna becomes available.
Shamsi's chinamen proved something of a mystery as he took 2 for 20 in four overs, which included having Paul Collingwood, one of the mainstays of Durham's innings caught low down at extra cover.
Chasing Durham's 161 for 7, Duckett initially stuggled to find his timing, despite scooping Chris Rushworth to fine leg for his only six in the third over.
But the left-hander always seemed to have things under control and it was a surprise when he reverse-swept to point with 29 needed off 3.2 overs. He made his runs off 56 balls and hit nine fours.
Durham's superior athleticism restricted their visitors' ability to run twos. Nor could Northants clear the rope with ease as it was pushed well back and Josh Cobb, the matchwinner in last year's final, was caught on the midwicket boundary.
Skipper Alex Wakely was also caught just inside the rope at backward square for 27 in the 18th over, leaving Rob Keogh and Steven Crook to score 18 off two.
Keogh collected two boundaries off Usman Arshad then hit James Weighell over mid-off for the winning four.
Jack Burnham lacked support in the closing overs of Durham's innings as he completed his maiden T20 half-century in the final over by stepping across to scoop Ben Sanderson to fine leg. That brought his third four and he added two big sixes in his unbeaten 53 off 41 balls.
Durham had hopes of reaching 180 while he was putting on 57 in six overs with Paul Collingwood, who also hit two sixes in his 38 off 28 balls. But once he was out to Shamsi - caught low down at extra cover - three more wickets fell to Rory Kleinveldt and only 35 runs came off the last five overs.