The striker rose highest to head home Robbie Willmott’s cross in the 81st minute to give the home side a deserved three points on a day that looked like it was going to end in frustration.
Chelmsford were guilty once again of missing some very clear chances in front of goal with Willmott missing the worst of them midway through the first half.
The visitors weren’t posing much of a threat sending the ball long at every opportunity and eventually City’s pressure told when Willmott beat Ollie Barnes to cross for Mullings whose header found the bottom corner.
It was the Clarets’ third straight win, Weston’s fourth straight defeat, as they head into Monday’s match with perennial title favourites Ebbsfleet United.
Clarets boss Rod Stringer was delighted with his side’s performance against Welling United last Monday and made just the two changes to his starting line up with Adam Bailey-Dennis coming in to make his full debut for City in place of Phillip Walsh and Bagasan Graham replacing Luke Daley.
Much like the win over Oxford City a week prior Chelmsford began to pressure from the first whistle and Shamir Mullings should arguably have put the Clarets in front after just four minutes when he headed wide from a Robbie Willmott corner.
City then had a big claim for a penalty fall on death ears before Willmott was found at the back post by Graham only to inexplicably shoot wide when the goal was gaping.
With the wind behind them Weston were looking at every opportunity to pump the ball forward, normally without reward, but the Clarets handed them a chance to take the lead when Dayle Grubb stole the ball off Bailey-Dennis leaving him through on goal only for him to slice harmlessly wide.
It was a huge let off for City who went straight back to putting the Weston back line under pressure, coming close to opening the scoring following a goal line scramble, before Anthony Church headed over.
Despite City’s dominance the two sides remained level as they went in to the break. Coming out for the second half the Clarets, with the wind now with them, were finding it too easy to just pump the ball up field.
But when Chelmsford did get it on the deck they were looking dangerous and almost took an early second half lead when Shaun Jeffers managed to beat goalkeeper Luke Purnell to the ball. But with the angle getting more acute by the second, Jeffers could only find the side netting.
Stringer’s side had another big handball shout go unrewarded before Mullings tried beating Purnell at a tight angle, but his shot was comfortably saved by the Weston number one, before Club Captain Billy Bricknell was introduced.
Bricknell’s introduction saw the Clarets go with three at the back as they went in search of a winning goal which duly came with just nine minutes of normal time remaining from the head of Mullings.
The combination of Willmott and Mullings struck again as the latter broke away from Ollie Barnes to allow him space to chip the ball towards the far post where the tall number nine was to flick his header into the bottom corner and send the Claret Army behind the goal into delirium.
With so little time left to find an equaliser the Clarets comfortably held out for the win and almost put the icing on the cake when in stoppage time Bricknell broke through down the left, forcing a superb save from Purnell to prevent Chelmsford wrapping up a third straight 2-0 win.
1. Ross Fitzsimons
2. Ashley Miller
3. Daniel Blanchett
4. Josh Rees
5. Adam Bailey-Dennis
6. Chris Bush
7. Robbie Willmott
8. Anthony Church (C)
9. Shamir Mullings
10. Shaun Jeffers
11. Bagasan Graham
12. Billy Bricknell (On for Daniel Blanchett 73’)
14. Phillip Walsh (On for Ashley Miller 90’)
15. Frankie Merrifield
16. Corby Moore (On for Shamir Mullings 87’)
18. Jake Reid
1. Luke Purnell
2. Sekani Simpson
3. Ollie Barnes
4. Kane Ingram
5. Jason Pope
6. Clayton Fortune (C)
7. Joe McClennan
8. Eliot Richards
9. Shaun McCoulsky
10. Dayle Grubb
11. Ashley Kington
12. Jordan Williams (On for Dayle Grubb 78’)
14. Danny Wring
15. Tom Meechan (On for Shaun McCoulsky 86’)
16. Lewis Powell
17. Darren Mullings
Chelmsford City: Shamir Mullings 81’
Chelmsford City: Adam Bailey-Dennis (Obstruction - 73’)
Weston-super-Mare: Kane Ingram (Foul – 41’)
Referee: Ian Fissenden
Assistant Referees: Simon Finnigan & Tom Bishop
City Man of the Match: Adam Bailey-Dennis