The Cobblers were beaten and failed to score for the second time in five days as Bradford City ran out winners at Sixfields.
Nakhi Wells, who scored a hat-trick at Northampton in this fixture last season, was again the match-winner, pouncing on a Danny East error to score the only goal of a 1-0 victory after 10 minutes of the second half.
It was another poor performance from Town, who did not look like scoring all night and who found their long-ball tactics completely nullified by the visitors.
Creativity was at a minimum and the game should probably have finished as a scoreless draw, with Wells’ presence of mind and sharpness the difference between the two sides.
But Aidy Boothroyd’s team did not create enough to lay claim to a share of the spoils and visiting keeper Jon McLaughlin enjoyed something of a night off.
His opposite number, Lee Nicholls, survived a scare on 12 minutes when he slid to collect a through-ball and lost it in contact with Wells before appearing to attempt to claw the striker’s legs from beneath him.
Nothing was given and the ball was then worked to Craig Forsyth, whose shot was well blocked by Kelvin Langmead and it squirted to the safe haven behind the goal.
Minutes later, Bradford somehow failed to score what look like it should have been a certain goal with James Hanson’s header scrambled off the line by Danny East as Town survived by the skin of their teeth.
At that point, there was little sign of the planned response to the Barnet result, with a solitary Alex Nicholls shot all the home side had to their name in a largely disappointing first 45 minutes.
The second period was not much better. It began with Wells’ goal, his fourth on this ground in just two visits and perhaps the easiest of the four.
A goal kick ran all the way through, East attempted to nod it back to Lee Nicholls but Wells was alert and alive and touched it past the advancing goalkeeper.
They should have doubled their advantage when Hanson blazed over the bar after Nicholls had parried Garry Thompson’s fierce shot on the run from 25 yards.
Town’s best chance game when Louis Moult, on as a substitute, arrived to meet a bouncing ball with his head, forcing McLaughlin to tip over his crossbar on the stretch.
But there was no more goalmouth action, with Bradford comfortably dealing with the long balls from the home defenders and the supporters greeting the final whistle with a chorus of boos.
Cobblers: L Nicholls, East, Langmead, Charles, Widdowson, Roofe, Tozer, Huws, A Nicholls, Platt, Akinfenwa
Subs: Moult (for Platt, 69mins)
Subs not used: Higgs, Demontagnac, Mukendi, Wilson, Hornby, Dias
Bradford City: McLaughlin, McArdle, Davies, Oliver, Meredith, Thompson, Ravenhill, Doyle, Forsyth, Wells, Hanson
Subs: Atkinson (for Forsyth 79mins)
Subs not used: Darby, Jones, Duke, McHugh, Connell, Hines
Attendance: 3,541
Away fans: 264