Saif Zaib posted a wonderful maiden first-class century before Ben Sanderson and Gareth Berg once again knocked over the Sussex top order in the LV= Insurance County Championship.
Talented left-hander Zaib, who has been at Northamptonshire since he was 15, collected a commanding 135 as he and Adam Rossington, 87, put on 198 together to help the hosts to a massive 335-run first-innings lead.
Sanderson and Berg, who shared all 10 of the first innings wickets, then claimed two scalps apiece to leave Sussex 68 for four. But Stiaan van Zyl’s 71 not out helped Sussex recover to 154 for four at the close at Wantage Road, still 181 runs behind Northamptonshire.
Northamptonshire added 227 runs in 51 overs as Zaib, Rossington, Berg and Tom Taylor all found scoring simple against a toothless Sussex attack.
The caveat to that was Ollie Robinson. The quick wouldn’t have done his England Test hopes any harm in front of ECB Performance Director Mo Bobat as he looked a constant threat for his five-for 58 – the 16th five-for of his career.
Zaib and Rossington were the morning protagonists as their partnership grew to 198, one short of the county sixth-wicket record against Sussex.
Milestones came in rapid succession as the skipper reached his third half-century in five innings this season in 90 balls, before Zaib converted to a hundred in 176 balls.
They fell either side of the second new ball as Zaib looked to up the ante. He added 35 in just 24 balls after reaching his century but was lbw sweeping Rawlins and Rossington miscued a pull to mid-on, with Wayne Parnell given out caught behind quickly after to give Robinson his fifth.
But Taylor and Berg crashed Northamptonshire over the 400-run batting point mark in a 63-run blast, before the former smashed 21 in two overs, after Berg had fallen, to bring the declaration on 416 for nine, Taylor unbeaten on 44.
Faced with a long task to reach parity, Sussex began their second innings with intent but soon collapsed to 68 for four in the face of Berg and Sanderson.
First-innings golden duck casualty Tom Haines raced to 18 off 17 before he expansively slashed Berg to a juggling Taylor at second slip.
Aaron Thomason edged Sanderson to Curran at fourth slip, Australian debutant Travis Head under edged a Berg short ball behind and Tom Clark saw his off-stump bail flicked off by Sanderson.
Brown and van Zyl negotiated the visitors to the close without further loss, adding 86 for the fifth wicket to leave Sussex 181 behind on 154/4 at the close.
Sussex 106 (Berg 5/18, Sanderson 5/28) & 154/4 (Berg 2/40, Sanderson 2/49)
Northamptonshire 441/9d (Zaib 135, Rossington 87)