Jesse Ryder returned 5-50 as Essex hung in the game despite Darren Stevens' rapid century for Kent in the LV= County Championship Division Two clash at the Spitfire Ground.
Ryder took two early wickets but Kent pair Daniel Bell-Drummond and Brendan Nash made half-centuries before Stevens thrashed 105 from 99 balls to put them in control on 344 for seven at stumps.
He was to become Ryder's fifth victim as the New Zealand all-rounder led a fightback, but Kent will perhaps be the happier with their opening day's work.
Home captain Rob Key won the toss before edging Ryder to Tom Westley at second slip, and the medium-pacer bowled Sam Northeast to leave Kent 35 for two.
But Bell-Drummond and Nash saw the batting side to lunch at 71 for two and gave them the upper hand with a superb performance during the afternoon session.
Nash brought up a 56-ball fifty and also the team's hundred from the first delivery of the 30th over and the West Indies international pressed on to 82 before he was caught behind off Tymal Mills - a late call-up after an injury to fellow left-armer Reece Topley - to end a stand of 113.
— Kent Cricket (@kentcricket) June 7, 2014
The more patient Bell-Drummond reached 50 two overs later but lost his new partner Ben Harmison when the former Durham man retired hurt having been struck on the hand by the fiery Mills.
Ryder removed Bell-Drummond, lbw for 56 from 172 balls after almost four hours at the wicket, to leave the tea-time score at 189 for four.
Sam Billings made just nine before falling to Ryan ten Doeschate but Stevens then took centre stage as he dominated a partnership of 95 with Adam Ball.
The all-rounder's half-century came up in just 52 balls, featuring eight fours as well as a six off Dutchman ten Doeschate, and he then hit three successive boundaries off Monty Panesar as his side moved effortlessly towards their second batting point.
Ball joined in the fun with two fours off the expensive Tom Moore (10-1-57-0), who was then hit for six as Stevens' strike-rate moved above a run a ball.
Three boundaries in one over from Mills took Stevens to three figures from 94 deliveries, featuring three maximums and 15 fours, but Ryder bowled Ball for 30 and then had Stevens caught by Moore in his next over.
Mitchell Claydon was unbeaten on 20 at the close, with Adam Riley on four at the other end and just Doug Bollinger to come unless Harmison is fit to resume his innings.