Northampton started the better at the PTS Academy Stadium with Joseph Mills trying to capitalise on a misplaced pass from James Shea, but the left wing-back’s attempted chip drifted harmlessly wide.
Town’s first attack in the 11th minute saw Elliot Lee, Harry Cornick and Luke Berry link up well, but the latter’s shot was deflected behind for a corner, from which Lee’s effort was also blocked.
Young Sam Beckwith impressed with some neat passing from left-back, and the Town were the side asking most of the questions with Berry and Cornick both firing wide with further openings in an uneventful first half.
Jones chose not to make any changes at the break, and again the hosts came out of the blocks quicker, with Mills shooting straight at Shea in the 51st minute.
But the Hatters were in front just after the hour, within seconds of Jones changing nine outfield players – keeper Shea and captain Sonny Bradley the only ones staying on.
Collins and Northampton defender Cian Bolger closed down keeper Steve Arnold as he attempted to clear, and the ball rolled into the Cobblers’ goal – Collins making sure it went over although replays suggested it came off Bolger.
It was two in the 77th minute when Ryan Tunnicliffe picked out Kazenga LuaLua’s run with a lovely ball over the top from deep inside the Hatters’ half. LuaLua scored for the second successive match with a lob over the onrushing Arnold.
Four minutes later Martin Cranie got in on the act, Clark’s right-wing corner flicked on by Bradley and a ricochet off a Northampton defender landing kindly for the former Sheffield United defender to volley into the top corner.
George Moncur went close to adding a fourth in the closing stages, but his cheeky chip after Collins played him into the box landed on the roof of the Cobblers’ net.
TOWN FIRST 60 MINS: Shea, Kioso, Pearson, Bradley, Beckwith, Rea, Berry, Mpanzu, Lee, Cornick, Hylton.
LAST HALF-AN-HOUR: Shea, Jones, Cranie, Bradley (Panter 82), Galloway, Tunnicliffe, Shinnie, Clark, Moncur, LuaLua, Collins.