Kent 259 (Davis 4-75) and 142 for 7 (Stevens 53*) lead Derbyshire 159 (Madsen 56, Stevens 6-47) by 242 runs
Ageless all-rounder Darren Stevens bagged 6 for 47 and smashed a quick-fire 53 not out with 11 boundaries during an action packed second day that saw 19 wickets fall and Kent build a priceless 242-run lead over Specsavers County Championship rivals Derbyshire.
Stevens, who turns 41 on April 30, appeared virtually unplayable when bowling his wicket-to-wicket 'dibbly dob' during a cloudy mid-session that saw Derbyshire lose their last eight wickets for 78 runs and concede a 100-run first innings deficit.
Batting for a second time by 4.45pm, Kent then stuttered themselves, losing seven wickets after tea before Stevens - the man his skipper has dubbed 'Benjamin Button' after the Brad Pitt movie character who ages in reverse - came in to dominate centre stage by clubbing his fourth championship 50 of the summer and his 74th of an illustrious first-class career.
With his star player still having a massage on the physiotherapists' bench, Sam Northeast, the Kent skipper said that Stevens is, in his opinion, the top championship player right now.
"It's like having the 'Stevo' of old back in the side," said Northeast. "When he came in near the end there the pitch was still doing plenty, but he just took it in his stride.
"He's relentless on his line and length and makes the ball talk, and he's in great form with the bat too. He's unbeaten with power to add and if he can help us get up near a lead of 300 we'll be in a really strong position. There's still a lot of cricket left, but I'd rather be in our position than there's."
Kent's openers had departed in quick succession; Sean Dickson, lbw prodding half-cock to Tony Palladino, while Daniel Bell-Drummond fenced to third slip to a Will Davis leg-cutter to go for 23.
After suffering a first innings golden duck, Joe Denly was bamboozled by a Davis slower ball and chipped to cover then, with only 49 on the board, Sam Northeast steered to second slip.
Will Gidman stretched in defence to gift keeper Gary Wilson a catch and Tony Palladino his 250th first-class wicket for Derbyshire, while Wayne Parnell heaved across the line to have middle plucked out by Tom Milnes.
Billy Godleman pulled off a stunning overhead catch at wide mid-off to account for Matt Coles, but Stevens and Adam Rouse continued to go for their strokes to extend the home lead well beyond 200 when play eventually ended a shade before 7pm.
Derbyshire had started their reply to Kent's first innings of 259 at 11.57am and were already deep in trouble by noon. Opener Luis Reece shouldered arms at Parnell's third delivery to lose his off stump and depart without scoring then, eight deliveries later, fellow opener Billy Godleman followed suit. Squared up by a full-length leg-cutter from Stevens, the visiting captain edged low to third slip where Gidman held a sharp, low chance.
Either side of the lunch break Wayne Madsen and Shiv Thakor led a partial Derbyshire fightback with an enterprising third-wicket stand worth 87 that ended when Thakor nicked a Stevens away-swinger to first slip.
That sparked a collapse that saw the visitors lose their last eight wickets in 22 overs as Stevens collected his third five-wicket haul in as many championship games.
Stevens trapped Darren Smit lbw prodding down the wrong line, as did Wilson, who lost his off stump to Stevens' late away swing. Then, after a nicely compiled 56 in two hours, Madsen erred in a late decision to shoulder arms against Parnell, allowing the ball to glance off the bat face to third slip, where Gidman snaffled a seventh catch of the campaign.
Stevens continued to mesmerise from the Pavilion End as Alex Hughes feathered a floating away-swinger to the keeper, then Milnes had off stump pegged back to give Stevens figures of 5 for 31 from a stunning, mid-session spell.
Matt Coles replaced Parnell to have Palladino caught at square leg, leaving James Harris to polish off the innings as Jeevan Patel edged leg-side to a tumbling Adam Rouse behind the stumps.
Madsen said: "When the bowlers get it in the right areas there's enough in this pitch to make it difficult to score. Shiv and I tried to bat with intent and hit their bowlers off a length but, even so, you felt there was always a ball with your name on it. Stevo has great skills as a bowler in these conditions that suit him down to the ground. With the bat, he's as clean a striker as you'll see. He's certainly had a day out today.
"What we fancied chasing they've gone past so we've got to get their last three wickets as soon as we can and then find a way to chase the runs but, if it gets above 280, we're under a lot of pressure."