The Steelbacks' hopes of reaching the quarter-finals of this season's Vitality T20 Blast are all but over after they suffered a heavy defeat at Derbyshire Falcons on Friday night.
The Falcons flew to their victory target to win by nine wickets, having bowled Northants out for just 100.
Rob Keogh top scored with 28, but it was a poor showing with the bat by the Steelbacks, who had won the toss and capitulated after being 83 for three.
Keogh took the only wicket to fall in the Falcons reply as the home side won with 17 balls to spare.
Northants are now bottom of the North Group, four points behind fourth-placed Derbyshire with just three games to play.
They knew the game at Derby would be key and the Steelbacks had set off like a train, but they were then derailed by a double-wicket maiden from Fynn Hudson-Prentice.
Richard Levi pulled Hudson-Prentice’s first delivery to deep mid-wicket and after Adam Rossington played across the line two balls later, only nine runs came from four overs.
The sight of a ball from Logan van Beek spitting and striking Keogh on the hand was not encouraging for the batsmen and the Steelbacks' hopes of setting a challenging total took another blow when Josh Cobb was run out going for a second by a direct hit from deep fine leg.
After 10 overs, the Steelbacks were 65 for three and the visitors spectacularly buckled under pressure as skillful seam and spin squeezed the life from the innings.
Alex Hughes was the main destroyer, having Alex Wakely caught at deep mid-off before Dwaine Pretorius sliced to short third man and Graeme White was caught behind.
Keogh failed to clear deep mid-wicket and when Ravi Rampaul polished off the innings to take his number of victims to 18 for the season, the Steelbacks had lost seven wickets for 19 runs in six overs.
Faced with such a modest target, there was no need for the Falcons to take risks, although Luis Reece swung Faheem Ashraf way back into the crowd behind the mid-wicket boundary in the fifth over.
Keogh trapped Reece lbw for 21 in the seventh over but Billy Godleman and Wayne Madsen made sure there was no late drama with an unbroken stand of 67.
Derbyshire Falcons: Reece, Godleman (c), Madsen, du Plooy, Hughes, Critchley, Hudson-Prentice, Smit (wk), van Beek, Rampaul, Rankin.
Steelbacks: Levi, Rossington (wk), Cobb (c), Wakely, Pretorius, Keogh, Ashraf, Sole, White, Sanderson, Muzarabani.