A brutal assault from South African Johannes van der Wath was enough to earn the Northants Steelbacks their third straight Twenty20 Cup victory at New Road.
Hosts Worcestershire looked favourites when the visitors began the penultimate over still needing 22 to win.
But paceman Gareth Andrew went for 23 as van der Wath smashed three sixes and a four to see Northants home on 142-4.
Worcestershire had earlier made 140-5, of which Stephen Moore top scored with 62 not out, his Twenty20 best.
It was supposed to be a day of celebration for Worcestershire as New Road legend Graeme Hick made his first public return to his old stomping ground since retirement to officially open the new £2million pavilion that has been named after him.
But it all turned sour late on a sun-kissed afternoon as van der Wath gave an example of the sort of cricketing brutality with which Hick himself used to bully opposition bowlers.
The South African one-day international clouted poor Andrew for 6, 4, 6, 6 in successive balls to dramatically end an afternoon that saw the Steelbacks go top of the Midlands/West/Wales Division.
From the first ball of the penultimate over bowled by Andrew, Niall O'Brien ran a single, then the newly arrived van der Wath got his eye in with a dot ball.
But, after smashing the next delivery over midwicket for six, he clouted the next for four before finishing with two towering sixes over long off into the New Road Stand.
Astonishingly, given how behind the clock they had appeared to be, at one point needing 50 off the last five overs, that won it for the Steelbacks with six balls to spare.
The powerful South African's unbeaten 29 had transformed a game that was drifting away from the visitors despite O'Brien's invaluable 48 not out from 38 balls. And Andrew was not the only one to suffer.
After claiming 2-10 from his first three very tidy overs, it was the 16 that came from Daryl Mitchell's last over which started to turn the tide Northants' way.
But, essentially, Worcestershire's continued failing at this form of the game (they have only twice made the quarter-finals in the seven previous summers of Twenty20) was again down to their batsmen not putting enough runs on the board.
Despite having so far won the toss in every game, it was also the third time in a week that they failed to reach 150.
Moore at least found some form with his 62 from 52 balls, his highest score in all cricket since returning from the England Lions tour to New Zealand in March.
But Worcestershire managed only 13 fours - eight of these to Moore - as Northants again showed why they are tipped as dark horses to reach the finals day at Edgbaston on August 15.