Devarn Green's early strike was enough for David Unsworth's side to return to winning ways with a gutsy win against a Chesterfield outfit whose recent blip continued.
They have now gone eight games without a win and dropped to fifth place in the table.
Latics took the lead six minutes in when Ellis Chapman crossed into the box and Green fired the ball home.
Ryan Colclough had a good chance for Chesterfield when his close-range effort went over the bar, and the midfielder then set up Bailey Clements, but his header went just wide.
Ollie Banks had a good chance for the Spireites five minutes after the break, but his curling effort went just over the bar and Paul McCallum forced Latics goalkeeper Magnus Norman to make two good saves.
Norman then made another great save to deny Liam Mandeville in the final 10 minutes for Latics to claim the three points in front a joyous travelling army of fans.
Latics are back in action on Tuesday when they travel to Barnet.
They are now a comfortable six points above the drop zone, and hopefully well on course for mid-table security.
