Essex 179 for 5 (Browne 61) trail Kent 387 (Kuhn 140, Robinson 78, Porter 4-107) by 208 runs
Nick Browne collected the 39th fifty of his first-class career but the Essex opener couldn't prevent Kent from maintaining their advantage in their Bob Willis Trophy contest.
Browne laboured against a consistent Kent bowling attack as he attempted to provide a backbone to the Essex innings.
He needed 139 balls to reach his half-century, but was dismissed for 61 - with only Varun Chopra also passing 30 so far in Essex's first innings of 179 for 5.
The visitors ended the day with a lead of 208, having posted a first-innings score of 387, with Marcus O'Riordan claiming his first two first-class wickets and Darren Stevens his 518th and 519th.
Kent had begun the day on 344 for 6, following a dominant opening to the newly formed, one-off, competition.
Heino Kuhn led the way with an imperious 140 but instead of kicking on in the morning he was lbw to Jamie Porter to the second ball of the day - with Essex taking the second new ball overnight. It was Porter's fourth wicket, as he ended with figures of 4 for 107.
O'Riordan would preface his later bowling efforts with a gutsy unbeaten 42, which along with Matt Milnes' 19, gave the away side some tail-end runs.
Simon Harmer had gone wicketless in 26 overs on the first day - somewhat a of shock for the South African following his haul of 71 scalps last season which had made him the leading wicket-taker in the County Championship and contributed towards him being named one of Wisden's Cricketers of the Year.
He only needed three balls to find his groove on day two, when Milnes top-edged a sweep to Porter at short fine leg, before finding Hamidullah Qadri's leading edge soon after. Harmer had a helping hand in rounding off the innings, as he pouched a catch at second slip when Ivan Thomas edged Matt Quinn.
Kent's total of 387 was the highest at the Cloudfm County Ground, Chelmsford, by a county in red-ball cricket since May 2014 - when Leicestershire totted up 433.
In reply, Sir Alastair Cook was leg before to Milnes in the ninth over.
Stevens, aged 44 and playing in his 24th professional season, used his nous to find Tom Westley pushing to Kuhn at second slip as Essex faltered.
Browne and Chopra then started to build the foundations for Essex, although on what had previously been a track easy to score on, they seemed to find scoring quickly difficult.
The pair put on 79 for the third wicket in 27 overs, with Browne forced to take his time to reach his 50 in the face of miserly bowling from Milnes, Stevens, O'Riodran, Qadri and Grant Stewart.
Chopra appeared on course to join Browne at the landmark, but handed off-spinner O'Riordan, on his second first-class appearance, his maiden professional wicket when he was bowled while attempting a paddle sweep.
Feroze Khushi quickly handed O'Riordan his second but it was mainly down to Jordan Cox's quick reactions at short leg.
Browne's vigil was ended when he slashed at a wide delivery from Stevens outside his off-stump, only to play onto his own stumps.
Adam Wheater and Ryan ten Doeschate made sure Essex didn't lose any further wickets before the close, but the 2019 County Champions remain firmly behind in the match.