Watch highlights of Essex's two-day victory
Essex crushed Leicestershire by an innings and 79 runs inside two days in the LV= County Championship Division Two clash at Grace Road.
The stunning win was the fifth in the last six four-day games for Essex and provided a massive boost to their promotion hopes, putting the pressure on second-placed Hampshire with one match to go.
Bottom-of-the-table Leicestershire were bowled out for 117 in 38.5 overs in their second innings, with the last six wickets falling for just four runs in five overs.
The humiliating defeat stretched Leicestershire's winless run in the championship to 31 games.
Essex captain James Foster hit his second successive century to steer his side to a total of 334, giving them a first-innings lead of 196.
Then David Masters, Jesse Ryder and 21-year-old Jamie Porter took three wickets each as Leicestershire collapsed from 48 without loss to 117 all out in the space of 25 overs.
Send your congratulations to @JamesFoster07 on his second hundred in two games using #FosterTon#LeivEsspic.twitter.com/q1h32MMBJd
— Essex Cricket (@EssexCricket) September 16, 2014
Leicestershire now have only one game left at Derbyshire next week to avoid becoming the first side since the Second World War to fail to win a championship game in two seasons.
Essex are at home to Worcestershire in their final game while Hampshire play Glamorgan in Cardiff as the battle for the second promotion place goes down to the wire.
Foster's 132 from 203 balls, with 19 fours and two sixes, was the cornerstone of the Essex innings that resumed on 153 for three at the start of the second day.
Ravi Bopara shared a fourth-wicket stand of 101 with Foster before dragging the ball back into his stumps trying to cut Rob Taylor when he was on 49.
But Foster continued to hold the innings together before being last man out when he was caught at mid-on off Charlie Shreck who finished with 3-82. Taylor was Leicestershire's most successful bowler, taking 5-67.
A lead of 196 looked more than useful but even Essex could hardly have imagined the home side would capitulate in such dramatic fashion.
WICKET And the match is over. Essex win by innings and 79. Charlie Shreck lbw to David Masters 0. Essex take 22 points. #LeivEss .
— Essex Cricket (@EssexCricket) September 16, 2014
Leicestershire reached tea at 16 without loss off seven overs and were on 48 in the 14th over when Angus Robson was lbw to Porter, who was playing in only his second championship game.
Porter then dismissed Ned Eckersley and Dan Redfern in successive overs to end a spell that brought him three wickets for 26 runs in seven overs.
And when Monty Panesar trapped Greg Smith lbw for 36 the collapse accelerated.
Josh Cobb hit 37 but no other batsman reached double figures as Ryder took 3-40 in 12 overs and Masters 3-15 in 11.5 overs, picking up the final wicket of Shreck with one ball to go before the extra half an hour would have been claimed.
Essex collected 22 points from the game and Leicestershire three.
Delighted Essex head coach Paul Grayson said: "We are in a good place with five wins in six games. Now it's all to play for next week."