LV= County Championship Division One, Cloud County Ground, Chelmsford (day three)
Essex 304: Browne 59, A Cook 58; De Caires 8-106 & 319-7 dec: A Cook 84, Critchley 65, Westley 47; Robson 2-36, De Caires 2-84
Middlesex 179: Porter 6-34, S Cook 3-43 & 147: Simpson 32; Harmer 5-43, Yadav 3-32, Critchley 2-17
Essex (21 pts) beat Middlesex (3 pts) by 297 runs
Simon Harmer once again played the lead role as Essex took the extra half hour to claim a three-day 297-run win over Middlesex.
Essex's prolific South African spinner took 5-43 to claim the 56th five-for of his first-class career to secure a sixth successive victory and help his side move back within 18 points of leaders Surrey.
Both now have two games left against the same opposition, third-placed Hampshire and bottom club Northamptonshire.
Essex host Hampshire at Chelmsford in their penultimate game, starting on Tuesday, 19 September, when Surrey host Northants at The Oval.
Then, a week later, Hants host Surrey, when Essex go to Northampton.
Harmer, Yadav & Critchley do the job
While Harmer passed 50 wickets for the sixth time in as many Championship seasons, he was aided by Matt Critchley (2-17) as three of the 10 wickets were taken by spin, along with a haul of 3-32 from Indian seamer Umesh Yadav on his debut.
Alastair Cook laid the foundations with a phlegmatic 84 from 178 balls before Critchley's belligerent run-a-ball 65 hastened Essex's declaration on 319-7 an hour after lunch.
Middlesex off-spinner Josh de Caires, son of former England captain Mike Atherton, added two second-innings scalps to his first-innings 8-106 to post the first 10-wicket match haul of his embryonic career.
When the visitors started their forlorn chase, Harmer then made immediate inroads as Sam Robson turned the off-spinner's second ball to England's Dan Lawrence who took a spectacular, full-length diving catch at leg slip.
A second Harmer wicket followed quickly when Joe Cracknell played back and was lbw before Jack Davies was caught at first slip off Yadav, who then also had Mark Stoneman taken at third slip before also bagging left-hander Max Holden, who was caught behind four overs after tea.
From 55-5, John Simpson and Ryan Higgins then stalled Essex for 19 overs to eke out 42 runs but, when Critchley switched ends, he turned one to have Simpson lbw.
Harmer's return after a brief break brought instant rewards when his third ball had Luke Hollman snaffled by Nick Browne at silly mid-off, before de Caires fell to the same catcher-bowler combination.
With eight wickets down, and the light fading on another sun-baked day, Essex claimed the extra half hour.
In the sixth additional over, Critchley bowled Higgins to end his two-hour vigil for 21 from 96 balls. And, with just seven minutes remaining before Middlesex could take the game into a final day, Toby Roland-Jones flicked a long hop from Harmer against Browne at bat-pad from where it ricocheted to wicketkeeper Adam Rossington, who dived to pouch the match-winning catch.
Essex leg-spinner Matt Critchley:
"That's six wins on the bounce now to keep the pressure on Surrey. That's probably as good as we've played on a wicket that was spinning, as we got over 300 twice.
"Ports bowled beautifully in the first innings and Harmy did the same in the second and, overall, it was as good as a performance that you could have hoped for.
"Yadav bowled really well, to get wickets on a flat wicket. He's obviously an international performer. That four-man attack with him, Simon Harmer, Jamie Porter and Sam Cook, the way they bowled in this match, is probably as good as you are going to get in this country. "
Middlesex captain Toby Roland-Jones:
"First innings, Joshie was massively impressive with the ball, used the conditions, bowled in good control, changed his pace and certainly made life tricky. They probably got 30 runs more than we would have liked, but I that gave us a way into the game if we could have drummed up a score.
"We can be pretty disappointed coming up as short as we did against seam on that wicket. But our answers on that wicket against a pretty good spin attack were pretty good.
"We're a bit disappointed that we weren't a bit more obdurate and made life a bit more tricky for them. But they are fighting at the top of the table for a reason. We need to go into our last three games confident that we can find a way of winning."