New signing Andros Townsend played an hour at Top Field, scoring the opening goal and going close with another couple of free-kicks before the Cobblers hit back to win by the odd goal in five.
Jake Burger had already gone close for the young Hatters with a 25-yard curler that whistled just past the post before former England winger Townsend’s free-kick caught visiting keeper Max Thompson out in the 28th minute.
Assisted by a strong wind, the inswinging delivery bounced down off the crossbar, with Millar Matthews-Lewis there to nod it in to make sure, but the assistant referee indicated the ball had already crossed the line.
Within two minutes, Townsend was firing another left-footed free-kick against the crossbar after Jayden Luker had been fouled, but this time the ball flew over the stand to Northampton's relief.
The former Spurs, Crystal Palace and Everton man then switched feet seven minutes into the second 30-minute period, bending a right-footer inches wide of the post after another foul on Luker, before Tyrell Giwa had to be alert to clear Northampton captain Peter Abimbola’s header off the line.
As the game entered the final third, Town introduced winger Joshua Phillips, Marcus Daws and Zack Nelson for his first outing since returning from 10 weeks out with an ankle injury, but Northampton equalised through Jamari Hart’s close range effort on 68 minutes, then took the lead on 77 minutes through a trialist.
Axel Piesold, Matthews-Lewis - with a jinking run into the box - and Burger all went close to equalising before Oli Lynch finally did in the 88th minute, diverting Daws’ effort in from all of two yards.
A draw was no less than the young Hatters deserved, with Under-16s centre-back Christian Chigozie, a 15-year-old, impressing during an afternoon off school up against a Northampton side that contained several senior players.
The visitors did have the final say, however, immediately going up the other end after Lynch's leveller to nick an 89th-minute winner with another close range finish from Neo Dobson.
Hatters: Horlick, Pinnington, Chigozie, Kayibanda, Giwa, Piesold, Luker (Nelson 60), Burger (C) (Daws 65), Townsend (Phillips 60), Lynch, Matthews-Lewis.Subs not used: Houghton, Lorentzen-Jones.
Goals: Townsend 28, Lynch 88
