Cheltenham Town produced a fine performance to pick up their second win on their travels in a fortnight under caretaker boss Russ Milton.
His side needed to respond to Tuesday night's disappointment in the Checkatrade Trophy and they did exactly that, turning in a display full of guile and attacking intent to take all the points.
Will Boyle had given the Robins a half-time lead, crashing home from close-range after a well-worked set piece.
It handed them the impetus and it stunned the home side, who struggled to rediscover their passing game.
They were handed a lifeline after the break, Kevin van Veen squaring the match from the spot after Cheltenham had got themselves in a mess, forcing Scott Flinders into drastic action and concede the penalty.
But they stuck to their task and responded with two more goals, substitute Conor Thomas scoring with his first touch of the match with a penalty of his own before Kelsey Mooney sealed the win seven minutes from time.
Milton made three changes to the side which lost out to Colchester United at the Jonny-Rocks Stadium last weekend, deploying a 4-1-4-1 formation that saw Nigel Atangana take a deeper role with Tyrone Barnett making his first start for the club.
Mooney (on the right) and George Lloyd flanked the former Port Vale striker and the plan worked a treat.
The home side had made a strong start and enjoyed the lion's share of possession during the opening 45 minutes but Cheltenham worked hard without the ball and for all the home side's promise, they went into the break a goal down.
Kevin van Veen had blasted over an early chance after he had raced onto a measured ball by former youth product Sam Foley.
Scott Flinders was called into a couple of comfortable stops to push away Jack Bridge's free-kick from an angle down the left, and to prevent Sam Hoskins from the edge of the box.
But neither efforts truly tested him and the Robins made them pay in the 36th minute after George Lloyd was clattered by Shay Facey down the left.
Jacob Maddox swung it in, Jordon Forster nodded it down and Boyle did the rest from close range.
A passage of poor play handed the Cobblers a route back into the game after the break, culminating in a rash moment from Scott Flinders who brought down Sam Hoskins after a poor pass from Boyle.
Veen stepped up and beat the Robins number one to his right to bring his side level.
But far from folding, Cheltenham responded well to the setback and found themselves back in front 13 minutes from time when Shay Facey tripped the outstanding Maddox, who caused no end of problems for the Northampton defence.
Thomas stepped up and squeezed it home, beating David Cornwell low to his right with his first touch of the match after replacing Lloyd in the closing stages.
Mooney added the third six minutes later, crowning a move down the left with a decent finish to claim his first goal for the club and send home the travelling fans happy.
NORTHAMPTON TOWN (4-4-2): Cornell; Facey, Taylor (c), Pierre, Buchanan; Hoskins, Foley, Crooks, Bridge; van Venn, O'Toole (Powell 46, Williams 65). Subs not used: L Barnett, Bowditch, McWilliams, Waters, Ward.
CHELTENHAM TOWN (4-5-1): Flinders; Forster, Mullins (c), Boyle, Field; Mooney, Maddox (Tozer 90), Atangana, Broom, Lloyd (Thomas 73); T Barnett (Kalala 85). Subs not used: Lovett (Gk), Duku, Clements, Alcock.
REFEREE: L Collins
ATTENDANCE: 4,608 (223 from Cheltenham)