Off-spinner Adam Riley enjoyed his best day in the County Championship for nearly three years to put his promotion-chasing side on course for victory over Derbyshire at The 3aaa County Ground.
Riley celebrated his first wickets in four day cricket since September 2015 as Derbyshire were forced to follow-on and ended the third day on 83 for 2, still 78 behind.
Wayne Madsen with 93 and 66 from Alex Hughes held up Kent until Riley snared them both and after the home side collapsed to 400 all out, he removed Billy Godleman and then Madsen for a second time.
The chances of Kent being in a position to put Derbyshire back in had looked slim when Madsen and Hughes batted through the first 95 minutes of the morning.
Kent’s pace bowlers made little impression and it was only when captain Sam Billings turned to his spinners that the wickets tumbled.
Riley, who has been troubled by injury in recent seasons, made the breakthrough when Madsen was lbw sweeping seven runs short of what would have been his 29th first-class hundred and four over later, Hughes chipped him to mid-wicket.
Derbyshire’s middle order subsided meekly with Matt Critchley stumped down the leg side as he wandered up the pitch and Harvey Hosein pouched at slip off a Joe Denly leg break.
Kent delayed taking the second new ball but when they did, Grant Stewart quickly struck with Hardus Viljoen edging a head-high catch to second slip before Sean Ervine was caught behind after batting for 31 overs.
Tony Palladino was run out 40 short of the 412 follow-on target but Lockie Ferguson and Hamidullah Qadri added 30 and delayed tea by one over until Ivan Thomas tempted Ferguson into a pull that was taken at fine leg.
It was the first time since 1901 Derbyshire had been forced to follow-on after scoring 400 and a pitch on which 961 runs had been scored was still a good one to bat on as Godleman and Tom Lace showed.
Matt Henry and Harry Podmore got little encouragement as the openers made another solid start and had negotiated 16 of the remaining 31 overs when spin again did the trick.
Godleman drove Riley through the covers for four but he misread the length of the next ball and was bowled playing back for 26 with his side still 110 behind.
Madsen had stood in Kent’s path for 65 overs in the first innings but this time he lasted only four before driving back a low return catch which Riley gleefully held to leave Derbyshire facing defeat.