Worcestershire 170 for 7 (Kohler-Cadmore 60, Cox 42*, Sanderson 3-34) beat Northamptonshire 169 for 7 (Duckett 50, Leach 3-26) by three wickets
Worcestershire broke the only unbeaten record in this season's NatWest T20 Blast and moved clear at the top of the North Group when beating Northamptonshire by Worcestershire by three wickets at New Road.
Wicketkeeper Ben Cox followed up three catches in Northamptonshire's 169 for 7 by taking the nine runs wanted from the last over in three balls from Mohammad Azharullah - a reverse paddle for four, a pull for four and a single into the covers.
Cox finished unbeaten with 42 from 24 balls, having turned the match in his team's favour after going in at 102 for 5, but it seemed that Worcestershire had lost their best chance when Tom Kohler-Cadmore was dismissed for 60 by Rob Keogh's juggling act on the deep extra cover boundary.
Keogh, who previously held a one-handed catch at mid-off from Brett D'Oliveira, knocked the ball up before completing the catch.
Both sides were handicapped by constant drizzle and poor light in Worcestershire's innings and at first the game was tilting towards Northants when Azharullah took two wickets in an over to leave the home side teetering on 20 for 3.
Earlier, Ben Duckett's first half-century of the season in the competition was crucial to setting up a challenging total for Northants, but the left hander benefited from two lapses in Worcestershire's normally reliable fielding.
This was rough luck on George Rhodes as the son of the county's director of cricket made his home debut following an impressive start in the Royal London Cup against Yorkshire earlier in the week.
The 22-year-old spinner was in his first over when Duckett, on 6, was dropped by Jack Shantry at short third man and returned later to see the batsman's second life, on 28, when D'Oliveira fumbled a stringing drive to extra cover. Rhodes had figures of 1 for 11 from his two overs, his wicket coming when Alexei Kervezee at deep square leg held a well-judged catch from Steven Crook.
Duckett went on to reach his 50 from 34 balls after hitting three sixes and four fours but without addition to his score he was seventh out at 140, bowled by Joe Leach as Worcestershire's acting captain finished with 3 for 26.
Leach was called on to lead the side when Daryl Mitchell suffered a side strain in the nets, a major blow to Worcestershire, who were already without paceman Matt Henry, but Northamptonshire were even more depleted with Richard Levi, Rory Kleinveldt and Olly Stone on their lengthening casualty list.
Wickets fell on a regular basis on a sluggish surface, although Alex Wakely, Josh Cobb and Keogh all had time to deal in some heavy blows.
Keogh was brilliantly caught overhead at mid-off as Shantry atoned for his earlier miss but the when he came on to bowl the penultimate over, Graeme White smashed three consecutive sixes.