The hosts were made to pay for a number of defensive lapses allowing the Clarets to comfortably come away with the three points at Privett Park.
Billy Bricknell returned to the side to open the scoring after picking up a loose header from Sam Pearce to send City into the break in front.
And within 10 minutes of the second half Chelmsford were assured of the points as they scored three goals in the space of six minutes.
The first came from Bagasan Graham who slide past Martin Rice. Rice then gave away a free kick after handling outside his area, Willmott recovered the ball after it was cleared, picking out Shamir Mullings whose chest down was smashed in by Josh Rees.
Mullings himself then scored as he was slid through by Bricknell, smashing the ball home from the edge of the area to wrap up the points with over half an hour to go.
Gosport’s captain Pearce then headed into his own net from a Willmott cross before Willmott turned provider again finding Bricknell for his second of the game and City’s sixth as they kept pace with the leaders Maidenhead United.
The home side’s misery was then compounded when Tom Bird was given a straight red card for an apparent elbow on Luke Daley late in the second half.
Having missed so many chances in front of goal earlier in the season Chelmsford had now scored 15 in their last three games having beaten Eastbourne 5-1 and Wealdstone 4-1 in their last two outings.
Rod Stringer made four changes from the side that defeated Wealdstone last weekend, three of which were enforced with Anthony Church, Mark Haines and Shaun Jeffers all out injured.
In came Billy Bricknell to skipper the side, Chris Bush returned from suspension and both Matt Young and Max Porter made their full debuts in place of Luke Daley and Church respectively.
Gosport made just the two changes from the side that lost in the injury time at St Albans with Aaron Dawson and Joe Oastler replaced by Mike Carter and Sam Pearce.
In midweek the Boro’ scored 19 past Saturday League side Widbrook United in the Portsmouth Cup. The Clarets themselves came to Privett Park in a rich vein of scoring form themselves scoring nine in their last two league games against Eastbourne Borough and Wealdstone.
Chelmsford had a good opportunity early on when Bagasan Graham slid the ball to Porter on the edge of the area but his shot was deflected wide for a corner.
Gosport Borough felt they should have had a penalty when Josh Carmichael went down in the area, but referee Sam Purkiss thought otherwise and booked the midfielder for a dive.
From the free kick Sam Pearce tried heading back to his goalkeeper Martin Rice but the defender got it all wrong, allowing Bricknell to get in and slot home and give the Clarets the lead.
It was Bricknell’s second goal of the season and his fifth in two games against Gosport having scored four in the last meeting between the two sides, a 6-1 win at Melbourne Park in April.
Gosport went on the front foot after going behind as a number of free kicks were lumped into the area. Fitzsimons had to make himself big to prevent Warren Bentley from scoring before Bentley failed to hit the target from another free kick, sending the ball over on the turn.
Bentley was proving to be the main threat for the home side as he got into another great scoring position but was prevented from getting his shot away by the toe of Chris Bush. Carmichael had a good chance too when he was picked out by a Cuthbertson cross but he shinned it wide.
Both sides were struggling to produce anything of real quality with passes going astray and shots going wayward but the Clarets were more than happy to go into the half time interval with a goal advantage.
With the rain coming down hard on the south coast, Gosport’s defensive woes continued as City scored three times in the space of six minutes early in the second half to all but seal another three points and their ninth game unbeaten.
The first of the three came through Graham as Rees stole the ball off the lax-Gosport defence. Mullings then outmuscled his man playing in Graham who slid under the advancing Rice.
Four minutes later and Rice fumbled the ball forcing him to leave his area in wet conditions, giving away a free kick on the edge of the area for handball and getting a yellow card in the process.
Robbie Willmott’s free kick was cleared in the first instance but he managed to barge his way back into the area, picking out Mullings who chested down to Rees who smashed home from close range.
Chelmsford would go on to pile more misery on the home side as they scored their 13th goal in three games when Bricknell stole the ball in the centre circle, dinking it through to Mullings who smashed home from the edge of the area.
The Clarets were in dreamland whilst Gosport were all at sea and City almost made it five when Graham’s low strike went inches past the post but the Clarets did eventually get their fifth and with another helping hand from the Gosport skipper.
After Graham had been replaced Willmott switched sides and his cross from the left was headed into his own net by Gosport captain, Pearce to make it five to the Clarets.
Chelmsford were not holding back and went on to score a sixth with Willmott once again the provider. From the left hand side again Willmott cut onto his right and picked out Bricknell at the far post who headed home his second of the game to round off the score.
To compound the home side’s miserable afternoon they finished the game with 10-men when Tom Bird was shown a straight red card for an apparent elbow on Luke Daley as the home side's discipline went out the window in the closing stages.
1. Martin Rice
2. T.J. Cuthbertson
3. Tom Bird
4. Mike Carter
5. Brett Poate
6. Sam Pearce (C)
7. Josh Carmichael
8. Ben Harding
9. Warren Bentley
10. Ben Wright
11. Dan Wooden
12. Ollie Bailey (On for Ben Wright 70’)
14. Jamie Barron (On for Josh Carmichael 70’)
15. Adam Wilde (On for Dan Wooden 63’)
16. Scott Walters
18. Lewis Watch
1. Ross Fitzsimons
2. Matt Young
3. Dan Blanchett
4. Josh Rees
5. Chris Bush
6. Phil Walsh
7. Robbie Willmott
8. Max Porter
9. Shamir Mullings
10. Billy Bricknell (C)
11. Bagasan Graham
12. Luke Daley (On for Bagasan Graham 69’)
14. Frankie Merrifield (On for Josh Rees 78’)
15. Max Cornhill (On for Max Porter 85’)
16. Anthony Church
Chelmsford City: Billy Bricknell 17’, 75’, Bagasan Graham 49’, Josh Rees 53’, Shamir Mullings 55’, Sam Pearce O.G. 72’
Gosport Borough: Josh Carmichael (Simulation – 16’), Martin Rice (Handball – 52’), Brett Poate (Foul – 81’), TJ Cuthbertson (Foul – 90’)
Chelmsford City: Daniel Blanchett (Obstruction – 71’)
Gosport Borough: Tom Bird (Violent Conduct – 87’)
Chelmsford City: None
Referee: Sam Purkiss
Assistant Referees: James Robinson & Colin Hubbard
City Man of the Match: Billy Bricknell