The Spireites hadn’t scored a goal since 4th October and hadn’t won a game since 17th September before today’s triumph over the U’s.
Welshman Ched Evans grabbed his first goal since the middle of August, volleying home the winner at the Colchester Community Stadium.
Jay O’Shea’s first-half opener ended a painstaking 502-minute wait for a Town goal, before Tarique Fosu-Henry levelled just after the break.
And victory broke the Spireites dismal run of seven successive defeats in all competitions.
Under pressure manager Danny Wilson made one change to the line-up that lost at Coventry, as both sides were looking for their first win in 10.
It was an enforced change for the visitors, as Burnley loanee Tom Anderson replaced the injured Sam Hird.
Evans came close to ending the visitor’s long wait for a goal as shot-stopper Sam Walker kept out his powerful drive.
In the 24th minute the travelling Spireites’ faithful were treated to a rare goal as O’Shea bagged his third goal of the season.
The play started with a clever interception from wing wizard Gboly Ariyibi, as Kristian Dennis played in the Irish midfielder who calmly slotted beyond the reach of Walker.
Mere minutes later O’Shea was denied a second as his curling effort was well kept out from Walker, with Evans striking the follow up agonisingly across the face of goal.
The U’s sprung into life heading into the break.
Kurtis Guthrie dived in ahead of Anderson but could only glance Drey Wright’s low cross wide of the target.
And Wright was the first to call Ryan Fulton into action. The breezy wide man skipped past a couple of visitors’ defenders with Fulton producing a top stop from a one-on-one situation.
Wilson’s charges suffered the worst possible start after the interval as mere seconds after the restart the U’s levelled proceedings.
Fosu-Henry, who only came on at half-time, scored with his first touch of the game.
And they nearly had a second a few minutes later as Luke Prosser powered his header off the bar.
Down the other end Evans nabbed the winner with a venomous volley.
O’Shea’s free-kick was met by Anderson’s head with the ball falling wonderfully for Evans.
Right at the end Fulton had to have his wits about him to deny Macauley Bonne’s effort from the edge of the box.
Bonne almost secured the hosts a replay in stoppage time with Fulton again on hand to scupper his powerful header.
Colchester: Walker, Brindley, Prosser, Wynter (Dunne 89), Eastman, Wright, Wright, Vincent-Young (Fosu-Henry 46), Slater, Guthrie, Szmodics (Bonne 79), Johnstone.
Unused subs: Lapslie, Kent, Barnes, Kamara.
Chesterfield: Fulton, Liddle, Evatt, Anderson, O’Neil (Nolan 67), Dimaio, Donohuem Ariyibi, Evans, Dennis (Graham 81), O’Shea.
Unused subs: Mitchell, Allinson, Simons, Maguire, German.
Attendance: 1840 (172)
Referee: Lee Probert