Chances were difficult to come by for long spells in the first half, but it was Crawley who created the first clear opportunity when a free kick was headed against the crossbar by Jimmy Smith.
However, it was Chesterfield who found the crucial opener in the 32nd minute when Eoin Doyle displayed great control to bring down a long ball before picking out the bottom corner.
That goal handed the control to the hosts, and the game was effectively over when Chesterfield struck twice in the space of two minutes early in the second half.
Jay O'Shea doubled the lead by using space on the wing to cut inside and curl home an impressive strike from outside the box, before Doyle took advantage of hesitancy in the Crawley defence to fire home his second of the evening.
Crawley struggled to produce a response to a disappointing start to the second half, and only Lewis Price's impressive stop from a Doyle strike prevented them from conceding a fourth just after the hour mark.
It would be Crawley who finished the game strongly, but they were unable to cause any late drama as Chesterfield eased to all three points.