An early goal from Billy Bricknell after just three minutes was cancelled out by Steve Cawley’s cheeky equaliser which was back-heeled into the net from close range.
City restored their lead with a tap in from former Concord player, Max Cornhill, and Cornhill was involved in Chelmsford’s third deep in the second half as he swung in the corner which was eventually smashed home by Josh Rees.
It was the first time Chelmsford had beaten the Beachboys in the Essex Senior Cup in five attempts having played the Canvey-based side in four of the last five competitions, losing each time.
The defeat also ended Concord’s stranglehold on the Essex Senior Cup which they had won in each of the last three seasons.
After the disappointment of Saturday afternoon's defeat to Poole Town, the Clarets took just three minutes to start putting that defeat behind them when Billy Bricknell opened the scoring.
A goal kick from Ross Fitzsimons was misjudged by former Claret, Marvin Ekpiteta, allowing the ball to skip through to Bricknell who confidently found the bottom corner with his first-time strike.
Chelmsford had a couple of half chances to extend their lead with Max Cornhill and Shamir Mullings flashes shots wide, but Concord levelled in flamboyant fashion through Steve Cawley.
Rob Girdlestone found acres to attack down the right before swinging in a brilliant cross onto the head of Sam Collins whose header across was eventually bundled over the line via the back-heel of Cawley.
Things weren’t level though for long as four minutes later City went back in front when Cornhill scored his first competitive goal of the season against his former side.
Bricknell managed to create enough space on the right to get a low cross into the box which wasn’t cleared by the Concord defence, with the ball eventually falling to Cornhill to tap home from close range.
Concord almost certainly should have been awarded a penalty when Chris Bush felled Tony Stokes in the area, but the referee was having none of it, waving away the home side’s appeals.
And late on in the half Ashley Miller almost gave City a two goal lead after some neat interplay from the Clarets, but the number two was denied by his opposite number, Girdlestone who somehow stopped the ball from crossing the line.
After a frenetic fast half the pace slowed down a tiny notch in the second half and the next goal was likely to be crucial to determining the outcome of the cup tie, but neither side could really create anything they would consider clear cut.
Some quick passing from the home side allowed James White to find some space on the left, but the recovering Church and Miller done well to get back and block the shot.
Mullings had a low strike bounce off the chest of Jon Miles in the Concord goal with no one around to mop up the rebound, and Cornhill’s far post header lacked the power to trouble Miles midway through the half.
With chances limited for either side Chelmsford extended their lead and put one foot in the 4th Round with their first clear opening of the second half when Josh Rees tapped in from a corner.
Cornhill’s in-swinging corner was volleyed towards goal by Adam Bailey-Dennis and was deflected onto the base of the post by the Concord defenders on the line, with Rees following up to smash home City’s third of the game.
Concord weren’t able to get one back to put pressure on the Clarets as their three-year stranglehold of the Essex Senior Cup was finally ended with Chelmsford advancing into tomorrow afternoon’s 4th Round draw.
1. Jon Miles
2. Rob Girdlestone
3. Ben Wyatt
4. Cameron Norman
5. Steve King
6. Marvin Ekpiteta
7. Sam Collins
8. James White (C)
9. Adam Topley
10. Steve Cawley
11. Tony Stokes
12. Jordan Brown
14. Jordan Chiedoze
15. Jay Dowie (On for James White 73’)
16. Audrius Laucys (On for Steve Cawley 83’)
17. Leon Gordon
17. Ross Fitzsimons
2. Ashley Miller
3. Chris Bush
4. Max Porter
5. Mark Haines
6. Adam Bailey-Dennis
7. Anthony Church (C)
8. Josh Rees
9. Shamir Mullings
10. Billy Bricknell
11. Max Cornhill
12. Luke Daley
14. Elliot Buchanan (On for Billy Bricknell 85’)
15. Robbie Willmott
16. Shaun Jeffers (On for Shamir Mullings 81’)
18. Frankie Merrifield (On for Max Cornhill 85’)
Concord Rangers: Steve Cawley 13’
Chelmsford City: Billy Bricknell 3’, Max Cornhill 17’, Josh Rees 74’
Concord Rangers: None
Chelmsford City: Chris Bush 54’, Max Cornhill 68’
Referee: Rob Whitton
Assistant Referees: Thomas Ramsey & Dean Skipper
City Man of the Match: Max Cornhill