Northamptonshire 528 for 7 (Holden 153, Rossington 112, Duckett 105, Hunn 3-90) trail Kent 701 for 7 dec (Dickson 318, Denly 182) by 173 runs
Northamptonshire batsmen Max Holden and Adam Rossington filled their boots in sublime batting conditions at Beckenham where Northamptonshire reached 528 for 7 in their first-innings reply to Kent's mammoth 701 for 7 declared.
The visiting fifth-wicket partners joined forces to bat through the entire mid-session and well into the final hour before Holden fell for a career-best 153. Soon after, Rossington followed him back to the pavilion for a season's best 112 leaving Kent's rookie seamer Matt Hunn to finish a tiring day with decent figures of 3 for 90.
Requiring 552 simply to avoid the follow-on, Northamptonshire resumed on their overnight score of 180 for 1 and suffered a huge blow to their survival aspirations when England batsman Ben Duckett perished to only the sixth ball of the day.
The diminutive left-hander, who hit a sublime double century on this ground last season, leant back to club Matt Coles' fourth ball through mid-on to move to 105 but, in aiming an expansive drive two deliveries later, Duckett edged behind to Sam Billings, who was standing in for Adam Rouse behind the timbers.
Coles gave way at the Beckenham End after a spirited seven-over spell of 1 for 26 to be replaced by Hunn, who also enjoyed success in his first over of the day. Alex Wakely, the Northamptonshire skipper, misjudged the line of Hunn's fourth delivery, shouldering arms to one that pegged back off stump to make it 219 for 2.
At the Worsley Bridge Road End, Pakistan wrist-spinner Yasir Shah whirled away in a wicketless, 11-over opening stint. He got the occasional delivery to turn, while one to Holden spat alarmingly from the footholds, only to balloon to safety.
Yasir then switched ends to bamboozle Rob Keogh with a darting top-spinner that rushed past Keogh's back-foot force to peg back off stump in the penultimate over before lunch. It proved to be Yasir's sole success from 34 overs bowled during the day.
Kent took the second new ball immediately after the restart and, despite lung-busting efforts by Coles and Mitch Claydon, they were unable to make any impact other than beating the outside edge half-a-dozen times.
Pretty soon, spinners Tredwell and Yasir were twirling away in tandem with three or four close fielders around the bat, but Northamptonshire stood firm with Holden, the Middlesex loanee, reaching a patient half-century from 146 balls, with only five fours.
Rossington, the more aggressive of the pair, needed only 59 deliveries to reach the milestone hitting seven fours and a six along the way as Kent continued to toil throughout the mid-session without success.
After tea, Holden, the wiry left-hander, notched his second century in Northamptonshire's colours from 216 balls and with 13 boundaries, while Rossington, seemingly content to bat time, went into his shell.
Holden received a healthy round of applause from the visiting dressing room balcony when passing 124 - his previous first-class best scored against Durham at Chester-le-Street last month - and they went up again soon after for Rossington's 100, scored off 132 balls with 11 fours and a six. It was his first ton of the summer and the sixth of his career.
Their run-fest and a stand of 239 ended when Holden, aiming an ambitious short-armed jab to a length-ball from Hunn, clipped to deep square-leg where Rouse, taking a rest from keeping, took a stunning diving catch on the ropes to send Holden packing after five hours at the crease.
Rossington followed just before stumps for 112. Wearily chasing a wide one from Hunn to be caught behind, then Coles came on to have Steven Crook well caught at second slip by James Tredwell to give Kent their sixth success of an arduous day in the dirt.