Cobblers made a losing start to the new football season when they opened their Sky Bet League Two campaign with an immensely frustrating 1-0 home defeat to Lincoln City at the PTS Academy Stadium.
Town followed an encouraging first-half display with a thoroughly disappointing second as they ran out of ideas in attack and lost concentration in defence, allowing Matt Green to head home the only goal of the game early in the second period.
Without being overly dominant, Cobblers had been the better team in the first-half should have held a half-time lead but they failed to make the most of several clear chances, Sam Hoskins and Daniel Powell particularly culpable after both saw one-on-ones saved by Lincoln keeper Josh Vickers.
They paid the price for those misses when Green headed home at the far post, and despite that being their only real chance of the game, it was enough for them to start the season with three points and leave Town empty-handed, the hosts missing another two clear opportunities to nick a point late on.
The Imps, beaten play-off semi-finalists last season, are a strong side expected to challenge for the title this year, so it should not be all doom and gloom.
But this was still a frustrating afternoon for Dean Austin's men, who simply cannot afford to be so wasteful if they are to mount a promotion challenge this term.
David Cornell was given the nod over Lewis Ward in goal while Matt Crooks partnered Shaun McWilliams in central midfield and John-Joe O'Toole played higher up, tucking in behind debutant Andy Williams.
Hakeem Odoffin was the other man making his full Cobblers debut at right-back, but Shay Facey and Junior Morais sat out having missed a large chunk of pre-season.
On another glorious afternoon and in front of a buoyant atmosphere all around the ground, Odoffin was at the heart of the game's first chance when his ball over the top found Hoskins whose cross was spilled by Vickers and dropped into the path of O'Toole but he couldn't force the ball home.
Hoskins then spurned a great chance himself, firing straight at VIckers having out-paced the home defence, and an even better opportunity went begging moments later when Daniel Powell, with time and space, failed to capitalise on an errant back pass, shooting tamely at Vickers.
Town were building momentum but that was disrupted somewhat by an early injury blow when McWilliams was forced off with a leg problem on 22 minutes, replaced by Jack Bridge.
Lincoln were less of a threat than their hosts but set-pieces caused the odd problem for Town while Harry Toffolo crashed a half volley just over the angle of post and bar.
Vickers was in the way again 10 minutes before half-time, thwarting the Cobblers for a third time when using his legs smartly to block from Powell, and that ensured his team remained on level terms at the break.
Town started the second-half on top but they were hit by the sucker-punch five minutes in when Lincoln scored with their first real chance of the game, Green losing Ash Taylor and nodding in Neal Eardley's cross from the right wing.
Cobblers sought a swift response and Bridge went close when dragging a shot wide but Lincoln, now playing five at the back, were happy to sit in and soak up pressure.
Town had all of the ball and most of the territory in the final quarter of the match but half chances and nearly moments were all they could conjure until late on, one of which saw Hoskins side-foot over from just inside the box.
The final minutes saw Northampton pour forward and they really should have earned a point, but Williams missed two glaring opportunities.
First he headed straight at Vickers when unmarked eight yards out and then again failing to beat Lincoln's goalkeeper having been put through on goal, rounding off a deflating afternoon.
Cobblers: Cornell, Odoffin, Taylor, Pierre, Buchanan, Crooks, O'Toole, McWilliams (Bridge 22), Powell (Bowditch 78), Hoskins, Williams
Subs not used: Ward, Barnett, Foley, Waters, van Veen
Lincoln: Vickers, Waterfall (c), Wharton, Frecklington, Eardley, Toffolo, Wilson, Bostwick, McCartan (Anderson 70), Akinde (Rhead 73), Green (Andrade 64)
Subs not used: O'Connor, Pett, Crookes, Smith
Referee: Lee Swabey
Lincoln fans: 1,453