Kent 633 for 8 dec (Harmison 123, Billings 100*, Bell-Drummond 81, Key 71, Denly 69) beat Essex 260 (Westley 77, ten Doeschate 54, Stevens 4-37, Haggett 3-54) and 166 (Hunn 4-51, Haggett 4-53) by an innings and 207 runs
A maiden first-class century from England one-day batsman Sam Billings and an extraordinary third-afternoon collapse by allowed Kent to land an innings and 207-run win over Essex in Tunbridge Wells with more than a day to spare.
A season's best 123 from Ben Harmison and an unbeaten 113-ball hundred by Billings eased Kent to a mammoth 633 for 8 declared - their highest ever total on home soil.
Having banked a first-innings lead of 373, Kent then skittled the visitors for 166 in a shade over three hours to bank 24 points for their first home win of the 2015 campaign. Essex, however, travelled home with only three points and with their promotion ambitions in tatters.
Kent had bossed the opening two days of the Royal Spa town festival week, but not even the most optimistic of Kent supporters would have believed Sam Northeast's side might wrap up their third win of the summer in such emphatic style.
Resuming on their overnight first innings score of 420 for 4, Kent pressed the accelerator right from the off but, with his score on 76, Darren Stevens chased a useful leg-cutter from Jamie Porter to nick to the keeper.
Harmison and Billings cracked on thereafter with the former reaching three figures for the first time in a year from 196 balls for his part in a sixth-wicket stand of 99.
Harmison was just short of his career best when he miscued a lofted drive to chip a simple catch to mid-on, but Billings, the impish wicketkeeper-bat, marched on reaching his first championship hundred in emphatic style from only 113 balls and with 46 runs coming in boundaries.
With a ground record score to their name, Kent declared moments later but, in the tense 18-over stint trough to tea, Essex capitulated to 66 for 4 to send the hosts into the break sensing blood and victory.
The Essex capitulation started as early as the second over when Nick Browne's push drive at a Matt Hunn length ball simply glanced off an open face to gully.
Jaik Mickleburgh played inside a Hunn off-cutter to have off stump pegged back, Ravi Bopara fenced outside off against Calum Haggett to be caught in the cordon then, in the over before tea, Jesse Ryder miscued an attempted lofted drive against James Tredwell to pick out Hunn fielding at mid-on.
The collapse gathered momentum after the break when Tom Westley edged an attempted glance to the keeper and dangerman Ryan ten Doeschate played back to a Darren Stevens leg-cutter to go lbw despite the hint of an inside edge.
Once James Foster feathered a back-foot force against the impressive Hunn to a tumbling James Tredwell in the slips the result was beyond doubt and Kent wasted little time in wrapping up proceedings.
After the win Billings said: "You could probably tell from my reaction that there was an element of relief to my celebrations at finally crossing the line for a hundred.
"I probably should have got there a lot sooner, not just at The Oval the other week, but at Guildford last year when I gave up the strike to Mitch Claydon and watched as he dollied one up in the air.
"It was a perfect team performance, if you were to sit down and plan a Championship win, that's sort of how you'd do it by building pressure with the ball and batting in partnerships. I was delighted for Ben Harmison who took his chance with an excellent ton, and for Matty Hunn and Calum Haggett.
"Hunny improves with every game he plays and has this knack of getting good players out and Calum got four for and another career-best, so we can all enjoy a day off knowing the job has been well done."