A Lee Novak goal four minutes from time was enough to give the Addicks their second successive home win.
There was a sense of relief when the goal went in, but it could not mask an uninspired performance.
Russell Slade made two changes from the team that started at Gillingham last week, with Patrick Bauer and Nicky Ajose coming in for Ezri Konsa and Johnnie Jackson.
Chesterfield used a fluid formation that switched between 3-5-1 and 5-3-1. The Addicks found the Spireites difficult to breakdown, but Ricky Holmes seemed the most likely to hold the key.
Bette noire, Ched Evans, posed the main danger to Charlton’s back line, but apart from a first half Dan Gardner effort that hit the far post, Cheserfield seldom troubled Declan Rudd.
The Addicks also hit the post in the opening period. Josh Magennis sent Ajose clear, but the pint-sized striker hit the woodwork, and Chris Solly blasted the rebound over.
Charlton gradually got closer in the second half. Magennis nodded a Holmes cross wide, and also got the ball in the net, but the whistle had already gone for a foul on the keeper.
Substitute, Jordan Botaka, sent a good cross in, but Ajose headed wide. Then, five minutes from time, Bauer’s header from a Holmes corner was saved, but the respite was brief.
A minute later, Holmes whipped in another dangerous cross from the left, but this time there was a decisive outcome. Lee Novak connected with a deft header to glance the ball beyond Ryan Fulton for the winner.
It was far from a classic performance by the Addicks, but in the end they were rewarded for their persistence.
Charlton’s Under-18 side beat Coventry 4-1 in their top of the table clash at Sparrows Lane on Saturday morning.
Charlton: Rudd, Solly, Bauer, Pearce, Fox; Holmes, Crofts, Ulvestad, Lookman (Botaka 70); Magennis, Ajose (Novak 81).
Subs (not used): Phillips, Foley, Konsa, Lennon, Jackson.
Goal: Novak 86.
Booked: Fox 17 (foul), Magennis 70 (simulation).
Chesterfield: Fulton; Graham (Dennis 88), Liddle, Evatt, Hird, Donohue; Dimaio, O’Neill, Gardner (O’Shea 66); Ariyibi, Evans (German 88).
Subs (not used): Allinson, Nolan, Denny, Maguire.
Booked: Graham 19 (foul).
Referee: John Busby (Oxfordshire).
Attn: 10,153 (422 Chesterfield).
TAGS: Charlton Athletic