Caleb Jewell and Wayne Madsen were once again in the runs on a high scoring day of Rothesay County Championship action at Derby.
Luke Procter’s 150 from 272 balls provided the launching pad for Saif Zaib, who hit three sixes to race to a second century in consecutive matches off only 86 balls.
With Justin Broad hammering 46 from 27 balls, the visitors declared on 500 for eight with a lead of 193 but their bowlers also struggled on a pitch which has flattened out.
Australian opener Caleb Jewell eased to a fifth 50 in six innings and with Wayne Madsen completing his second half century of the game, Derbyshire moved to 202 for three at stumps, a lead of nine.
Procter faced 17 balls to get the three runs needed to complete his 9th first-class hundred but from then on, the visitors moved swiftly through the gears.
When the second new ball was taken, Rob Keogh drove Luis Reece for four to bring up the 300 and the 100 stand which had come from 164 balls.
Keogh reached his 50 by pulling Reece for another boundary but in the same over he went for a big drive and was bowled .
Zaib survived a hard chance to second slip on one and he took full advantage as he tore the bowling apart either side of lunch.
Procter passed his previous highest score, an unbeaten 144 against Warwickshire at Northampton in 2022, and then pulled Zak Chappell for his 20th four to reach 150 before cutting Blair Tickner into the hands of gully.
But Derbyshire were struggling to stem the flow of runs with Zaib taking 14 off a Martin Andersson over as 139 runs came in the first session.
The lead at the interval was 68 and although Lewis McManus was caught behind sweeping at Jack Morley, the game quickly ran away from Derbyshire who had to bowl spin at both ends to improve a slow over rate.
Zaib and Broad tucked into the post lunch smorgasbord to plunder 85 from 54 balls before the latter was caught at deep midwicket to give Madsen his first championship wicket since April 2022.
When Zaib skied Morley to long off, the declaration came giving their bowlers 54 overs to try and put Derbyshire under pressure but the batters continued to dominate.
David Lloyd needed a big innings after a run of low scores and started positively, pulling Liam Guthrie for six, but then fell to a stunning catch by Broad who leapt at cover to hold on at the second attempt.
But Jewell again looked untroubled and with Harry Came, reduced the arrears to under a hundred before Dom Leech trapped Came on the crease in the 27th over.
Jewell responded by pulling Leech for his seventh four to reach 50 and with Madsen, set about deflating Northants’ hopes of victory.
The pair added 66 from 84 balls and although Jewell cut Broad into the hands of first slip, Madsen passed 50 for the fourth time this season to put his team in credit by the close.
Derbyshire opener Caleb Jewell said: “I’m hoping there is something more around the corner but I’m happy with how I’m playing, I just need to sustain it for a bit longer.
“In those situations you can probably just try and bat for time and hope you can stick in there long enough to dwindle it down but I think it’s important to keep scoring the runs as well so now we’re in front we can make a few more plays in the game if we need to.
“It doesn’t really change the way I go about my batting, if we’re leading or behind, I know what’s best for me and that was how it was today.”
