Max Holden's maiden century in only his sixth first-class game left Durham kicking themselves for dropping him twice early on the second day of their Specsavers County Championship match at Chester-le-Street.
Once the England Under 19 captain, on loan from Middlesex, had departed for a stoical 124. Northamptonshire lost all their last three wickets on 338 and in 22 overs Durham reached 78 for one in their second innings, trailing by 94.
Paul Coughlin's manful efforts to carry the depleted Durham attack earned him a maiden five-wicket haul. He had five for 49 in 27 overs, while fellow seamers Barry McCarthy and Gavin Main went at almost five an over.
Resuming on 19, Holden survived scares from the day's first and seventh balls. After a confident lbw appeal from McCarthy he edged Coughlin at comfortable height to second slip, where Keaton Jennings spilled the chance.
Then on 27 another straightforward catch was missed by Graham Clark at point off McCarthy, but Holden knuckled down and spent 140 balls over his first 50.
With conditions far more benign than on the first day, Durham were made to pay a heavy price for their lapses and three more chances went down as Holden put on 96 for the fifth wicket with Adam Rossington and 162 for the fifth with Josh Cobb.
Rossington hit nine fours in his 59-ball 50 before dabbing wide of off stump at McCarthy to edge to second slip and depart for 65.
He paved the way for Cobb to take advantage of Durham's toils with some belligerent strokes in making 96 off 133 balls.
He hit 11 fours and a six before edging to second slip during a probing new ball spell from Coughlin.
Holden, becalmed on 85, had exasperated Paul Collingwood, who troubled the left-hander with away swingers.
And it was one of those which finally found the edge to give Stuart Poynter his fourth catch, ending the youngster's 228-ball vigil.
The importance of his innings was underlined by Northants losing their last five wickets for 11 runs.
With much less assistance than on the first day, the visiting seamers could make little impression, although Ben Sanderson had a big lbw appeal against Stephen Cook.
Badly in need of runs before joining the South African Test squad, Cook was dropped by Rory Kleinveldt at third slip on 16 off Nathan Buck.
After digging in to reach 23 he took a fancy to Rob Keogh's off spin, taking 11 off his first over, only to see Jennings stumped for 27 off Keogh's ninth ball when he tried to paddle him to fine leg and lifted his back foot.
It was a bit of a brainstorm from Jennings with only four overs left, but McCarthy survived as nightwatchman and Cook was on 39 at the close.
Speaking at the close of play, top performer Holden said: "You dream about scoring your first hundred so it was a special moment. I had to work hard on a tricky pitch and had a bit of luck, but you put the dropped catches behind you and take the next ball. It's important when you get in to make it count."