Graham Napier once again proved the thorn in Hampshire’s side as he sent them crashing to a first Championship defeat of the season.
The Essex all-rounder had already struck 74 in the first innings to earn the hosts a 57-run lead.
And after Hampshire had staged a brilliant fightback yesterday, Napier hammered 78 not out to douse the flames and extinguish any hope the visitors had of claiming a miraculous success in Chelmsford.
Essex were staring down the barrel at 31 for six – chasing a modest victory target of 143 – when Napier strode to the crease.
After David Balcombe (two for 32) bowled England captain Alastair Cook (four), the home side lost five wickets for just 15 runs.
Aussie George Bailey produced two run outs, while James Tomlinson (two for 38) had Rob Quiney (10) caught behind and Ben Foakes trapped leg before wicket in consecutive deliveries to leave Essex in disarray.
But just as Hampshire contemplated the most unlikely of smash-and-grab raids, Napier launched the counter-attack.
Mark Pettini (35 not out) played second fiddle to the all-rounder, whose 88-ball demolition included 10 fours and three sixes.
It left Hampshire, who sat second going into the match, needing to regroup after the first setback to their division two promotion charge.
Earlier in the day, James Vince (67) and Liam Dawson (52) had offered crucial resistance and helped the visitors edge to 199 all out.