Williams fired the Clarets in front a minute before the interval before Billy Bricknell spurned a great chance to make the lead more comfortable on the stroke of half-time.
Maidstone sat four points off leaders Ebbsfleet with two games in hand prior to kick-off but failed to pass through a resilient Chelmsford back-line as they held on for a crucial victory to aid their fight against relegation, with Williams and substitute Luke Daley striking late on to seal the victory.
The win will be an added bonus for the Clarets who have two crunch ties against similarly placed Bath City and an away trip to Havant & Waterlooville coming up in their next two matches.
Caretaker boss Kevin Maher named an unchanged team from the side that fell to a 1-0 defeat at Concord Rangers on Saturday, meaning that top-scorer Bricknell lined-up to face his former employers. Maidstone, meanwhile, had to make an alteration to their starting eleven after skipper Joe Healy pulled up in the warm up, giving ex-Claret Jack Paxman a chance to fill in.
The Clarets made a positive start to the match in a bid to arrest their poor recent form that had seen them without a win in three matches, with Sandro Semedo testing the gloves of Lee Worgan from distance, forcing the ‘keeper into making a fairly routine stop.
It was a more resilient and dogged display from the Clarets after Maher bemoaned the side’s lack of fight on Saturday, with the midfield duo of Mark Hughes and Reece Prestege winning some early midfield battles.
Chances remained at a premium for the hosts although Maidstone had Bobby-Joe Taylor to thank for keeping the score level as he cut out Bricknell’s cross that would’ve presented Prestedge with an easy tap-in at the back post.
Semedo then had an excellent chance to play in Bricknell who was free to his right but the Leyton Orient loanee decided to go it alone before blazing an effort disappointingly wide as what looked to be a promising counter-attack petered out.
Just as the Clarets looked as if they were going to settle for a 0-0 score-line at the break, Jason Williams popped up with a fine individual goal a minute before the whistle. Some impressive pressing from Bagasan Graham Chelmsford forced Maidstone into a rushed clearance that the Southend loanee pounced on before working his way towards goal and firing a low shot past the stranded Worgan. Elation around the Melbourne Community Stadium followed.
That mood could have been heightened had Bricknell tucked away a golden opportunity from eight-yards on the stroke of half-time, but the former Maidstone striker failed to get a clean contact with the goal gaping from Williams’ timely cut-back.
The miss kept Maidstone firmly in the game and Jay May almost halved the deficit within a minute of the restart, dragging a shot wide with Christian Dibble scrambling to cover his near post.
May lifted Vas Karagiannis’ pacey cross from the left over the bar after the Clarets had regained control of the match, although Bricknell could have doubled the lead moments before but a heavy touch inside the box allowed Jay Saunders’ side to thump clear.
Semedo came closer still to giving the Clarets an added cushion with less than 20-minutes remaining but Worgan was equal to the thumping effort from inside the box after the winger latched on to a loose ball.
Hughes then appeared to be bundled over in the area but the referee waved away their protests a minute after a handball appeal from the visitors wasn’t given.
That didn’t matter though as Williams added a second two minutes from time, striking low past Worgan after a fine solo run that Maidstone failed to cut out.
Substitute Luke Daley added gloss to the win in stoppage time when he cut inside before curling an unstoppable effort into the top corner to a chorus of cheers from the City faithful packed behind the goal as they recorded their third consecutive home win.
It was the perfect reaction from the poor performance at Concord, and one that the Clarets will need to build upon as Bath City visit next Saturday.
1. Christian Dibble
2. Rob Girdlestone
3. Marvel Ekpiteta
4. Mark Hughes (C)
5. Mark Haines
6. Rory McAuley
7. Sandro Semedo
8. Reece Prestedge
9. Jason Williams
10. Billy Bricknell
11. Bagasan Graham
12. Luke Daley (On for Sandro Semedo, 82’)
14. Harry Morgan
15. Marvin Ekpiteta
16. Lee Sawyer
18. Timothy Monsheju (On for Billy Bricknell, 90+2')
1. Lee Worgan
2. Bobby-Joe Taylor
3. Tom Mills
4. Callum Davies
5. Manny Parry
6. James Rogers
7. Vas Karagianni
9. Jay May
10. Dan Sweeney
11. Alex Flisher
17. Jack Paxman
12. Will Thomas
14. Alex Akrofi (On for Alex Flisher, 56’)
15. Jack Richards (On for Jay May, 80’)
16. Adam Birchall (On for James Rogers, 74’)
Referee: Mr. Sam Purkiss (London)
Assistant Referees: Mr. Nathan Walker and Mr. Oliver Morris-Sanders
Bookings: Chelmsford City: Rory McAuley (49’, foul)
Maidstone United: None
Scorers: Chelmsford City: Jason Williams (44’, 88’), Luke Daley (90+4')
Maidstone United: None
HT Score: 1-0
FT Score: 3-0
City Man of the Match: Jason Williams