Cobblers paid the price for a wretched first-half performance as they suffered successive home defeats when beaten 2-1 by Gillingham at Sixfields on Tuesday evening.
It was thought that it couldn't any get much worse than their dismal display against Rochdale 10 days earlier but, for 45 minutes on Tuesday, this was easily the worst Town have played all campaign.
Ran ragged at the back, bossed in midfield and toothless up front, Town were lacking in all areas of the pitch as they were outwitted and outclassed by a slick Gillingham outfit.
The visitors' 2-0 lead at half-time, given to them by Josh Parker and Tom Eaves, was the very least they deserved after playing the home side off the park on their own patch.
Thankfully, the Cobblers did improve in the second period and Ash Taylor's deft header transformed the atmosphere around a previously frustrated Sixfields, but ultimately it wasn't enough for prevent defeat.
Despite giving it a much better go after half-time, Town could not complain at the final score after an opening 45 minutes that simply fell way below par, leaving manager Jimmy Floyd Hasselbaink with plenty of problems to solve with his team slap bang in trouble again, just one point and one place above the bottom four ahead of Saturday's tough game at fifth-placed Scunthorpe United.
Hasselbaink had hinted at making changes following the win at AFC Wimbledon just three days earlier and that was indeed the case with Matt Crooks replaced by Sam Foley and Chris Long coming in for Kevin van Veen, who missed out due to a minor knock picked up at Kingsmeadow.
Both of these two sides came into this game on a run of good results but only one started with the confidence of a team in form and that was the visitors.
With Cobblers barely out of the starting blocks, Gillingham required just six minutes to hit the front through Parker, who hammered into the top corner from 20 yards after latching onto a poor defensive header and running unchallenged at the home defence.
The goal didn't wake Town up, far from it, as Gillingham remained completely and utterly dominant as they sensed the chance to put the game to bed before it had ever really started.
Eaves missed a glorious chances to double their advantage five minutes after Parker's opener, somehow clearing the crossbar from just four yards, but Northampton did not heed their warning and a few moments later it was 2-0.
The hosts just couldn't get to grips with the visitors' 3-5-2 as Gills constantly found space between the lines and their pressure was rewarded with a second goal as Eaves poked in Luke O'Neill's drilled cross.
The goal was greeted by boos from the disgruntled and somewhat perplexed home fans who couldn't believe what they were witnessing as Gills continued to totally boss things.
The visitors were first to every ball and played with pace and fluency, qualities that were distinctly lacking in the home team's play.
Chances did at least dry up for Gillingham but their control of the game remained as tight as ever and they still could have had more goals before half-time with Parker's header ruled out for a tight offside call and Eaves shooting wide from 20 yards.
Eaves and Parker had bullied the home side's defence and run them ragged throughout the half while Gills also bossed the midfield and limited Town to very few attacks of note.
It was unsurprising that Hasselbaink felt compelled to change things at half-time, bringing on Hildeberto Pereira for Foley, but Gillingham again came out firing and Parker saw his shot blocked by Ash Taylor.
There then followed a rare period of Northampton pressure and, at the end of it, they had a goal to change the atmosphere around Sixfields.
A neat piece of skill from Long won Town a free-kick 35 yards from goal and Grimes' delicate delivery was expertly guided into the corner of the net by Taylor's back header.
That gave the Cobblers an unlikely lifeline and Hasselabink swiftly sent on Gboly Ariyibi in attempt to seize on the momentum that was gradually building.
His side were close to an equaliser too when, on the hour-mark, Tomas Holy reacted late to claw away Ariyibi's low shot, with Long's follow-up effort blocked.
Gillingham, having been so superior before half-time, had receded into their shells in the second-half and looked increasingly rattled as the hosts pressed for a leveller.
Pereira volleyed over and O'Toole side-footed wide but the Cobblers could not muster much else as they toiled for an equaliser despite the introduction of debutant Boris Mathis as a late roll of the dice.
Parker should have sewn it up for Gillingham when heading wide from barely two yards out in the final 10 minutes but that miss didn't come back to haunt him as Town just could not get going again and the visitors comfortably saw it out.
And it got worse for the home side after the full-time whistle confirmed defeat with Pereira needlessly shown red for remonstrating with referee Craig Breakspear and picking up a second yellow card for his troubles.
Cobblers: O'Donnell, Moloney, Taylor (c), Turnbull, Bunney, Foley (Pereira 45), Grimes, O'Toole, Hoskins (Ariyibi 56), Powell, Long (Mathis 83)
Subs not used: Cornell, Barnett, McWilliams, Crooks
Gillingham: Holy, O'Neill, Ehmer, Zakuani, Nugent (Martin 71), Ogilvie, Byrne, Hessenthaler, Reilly (Wagstaff 71), Eaves, Parker
Subs not used: Hadler, Garmston, Moussa, List, Wilkinson
Referee: Charles Breakspear
Gillingham fans: 419