The City skipper put the visitors ahead after 71 minutes as he stabbed an effort from close range between Deren Ibrahim’s legs.
Clarets boss Rod Stringer made no changes to the side that conceded a late equaliser to draw 1-1 with St Albans City last week, with Elliott Buchanan looking to find his shooting boots once again after going close to netting so many times last week without success.
The visitors had the first chance of the game when Anthony Church spotted Josh Hill at the far post with a delightful cross-field pass, however the defender was unable to control well enough and the ball rolled out of play.
The Clarets continued their dominance in the opening ten minutes when Hill won a throw-in on the near side as Robbie Willmott looked to beat Alex Wynter on the right wing.
City were making plenty of chances but were just unable to convert them, however the Clarets’ attacks were constantly broken down by Tom Bonner’s repetitive off-the-ball fouling of Shaun Jeffers.
The hosts’ first chance of the game came after 16 minutes as a loose ball found a Dartford striker who poked a shot at Fitzsimons from close-range, although the City shot-stopper was on-hand to deal with the effort easily.
A lack of communication almost gave the hosts an opener when Wanadio exploited the mistake before shooting, however his shot was straight at Fitzsimons.
Bonner was finally penalised for his repetitive fouling on Jeffers as the striker raced away, whilst Willmott had the ball, and the striker was tussled to the ground – leaving Whistler Sam Purkiss no choice but to book the defender.
The Clarets had another chance to open the scoring when Buchanan’s intricate chipped ball found a driving Jeffers, but Harris chested the ball down to Ibrahim.
Spillane became the first Claret to enter the book as he bundled over Bradbrook before kicking the ball away.
The hosts started the second half brightest, with Fitzsimons almost granting them an easy goal as he failed to control Hill’s back-pass. Wanadio curled in the successive corner where Ronnie Vint sent his header smacking into the crossbar.
Elliot Bradbrook came close for the hosts again, however the midfielder’s long range half-volley flew just wide of the post.
Ibrahim kept the scores level with a sensational double save on 55 minutes. The ball was worked across the box to Willmott who drove a shot at Ibrahim before the rebound fell to Jeffers who had a weak header turned over the bar.
Stringer made his first change just past the hour-mark as he introduced Liam Enver-Marum for Elliott Buchanan.
The hosts came close to an opener as Vint latched onto a loose ball from forty-yards, however the full-back was unable to keep his shot low and it flew well over the bar.
The Clarets eventually took the lead as a loose ball bobbled around the box. Substitute Enver-Marum saw his shot blocked and the ball ricocheted to Church who poked his shot through Ibrahim’s legs.
Wanadio had a chance to level the scores as he skipped past Church and Michael Spillane, but the speedy winger could only spill his shot at Fitzsimons.
The hosts had loud claims for a penalty waved away as Wanadio weaves his way into the box before being tugged down by Spillane.
The visitors should have doubled their lead on 90 minutes as Enver-Marum stabbed a shot from two-yards which looked destined for the bottom corner, but Vint appeared from nowhere to smack the ball away.
It proved to be the last action of the game as City held on for an incredibly important win as they went on their charge to the play-offs.
1. Deren Ibrahim
2. Danny Harris (88’, off for Richard Seixas).
3. Tom Wynter
4. Tom Bonner
5. Ronnie Vint
6. Keaton Wood (76’, off for Alex Brown).
7. Ryan Hayes
8. Elliott Bradbrook ©
9. Tom Murphy (81’, off for Shai Thorley-Porter).
10. Andy Pugh
11. Luke Wanadio
12. Alex Brown
14. Richard Seixas
15. Michael Habte
16. Shai Thorley-Porter
17. Tony Coxall (GK)
1. Ross Fitzsimons
2. Josh Hill
3. Bagasan Graham
4. Max Porter
5. Chris Bush
6. Michael Spillane
7. Robbie Willmott
8. Anthony Church © (78’, off for Max Cornhill).
9. Shaun Jeffers (81’, off for Chris Dickson).
10. Elliott Buchanan (62’, off for Liam Enver-Marum).
11. Josh Rees
12. Chris Dickson
14. Max Cornhill
15. Liam Enver-Marum
16. Kane Haysman
18. Luke Daley
Chelmsford City: 33’ Michael Spillane, 90+3’ Josh Rees,
Dartford: 28’ Tom Bonner.
Chelmsford City: 71’ Anthony Church.
[b] Half Time Score: Dartford 0-0 Chelmsford City
City Man of the Match: Anthony Church.
Referee: Sam Purkiss, assisted by Lee Grimsey and Mark Stevens.