Morecambe took another step towards League Two safety after picking up their third consecutive home win.
Substitute Liam Mandeville proved the matchwinner at the Globe Arena, heading home Zak Mills’ cross in the 82nd minute for his first goal since scoring the winner at Grimsby Town in September.
It lifted the Shrimps to 18th in the table, nine points clear of the bottom two with half-a-dozen games left of the season.
Mandeville’s goal was the one moment of genuine attacking quality on display in a largely scrappy game.
Morecambe boss Jim Bentley had made one change from the side beaten at Swindon Town with club captain Barry Roche recalled in goal for his first game since the end of October.
Most of the first-half action was centred on Roche’s goal with Crawley the likelier of the two sides to score.
Joe McNerney and Tom Dallison headed corners off target, while Roche kept out a low shot from Ashley Nathaniel-George after he had cut inside from the left.
The closest they came was 11 minutes before the break when Ollie Palmer headed Joe Maguire’s ball back across goal and Reece Grego-Cox hit the top of the bar with an overhead kick.
Palmer sent another Maguire cross off target before the break, while in contrast, Morecambe struggled to make much headway going forward.
Aaron Wildig fired well over from 18 yards and Richie Bennett saw an effort from a tight angle comfortably saved by Crawley keeper Glenn Morris.
A more even second half saw both sides generally fail to impress, though a poor playing surface did not help.
Maguire and George Francomb sent efforts off target, as did Morecambe winger Piero Mingoia at the other end.
Morris easily held a Mandeville effort but, moments later, was powerless to prevent the substitute from heading home to settle matters.
There was still time for another replacement, Kevin Ellison, to drag a shot wide from 18 yards but one goal proved enough in the end.
Morecambe: Roche, Mills, Old, Lavelle, Conlan, Kenyon (Fleming 62), Wildig, Mingoia, Collins, Oates (Mandeville 62), Bennett (Ellison 75). Subs not used: Halstead, Brownsword, McKay, Cranston.
Crawley Town: Morris, Young, McNerney, Dallison, Maguire, Morais (German 83), Bulman, Camara (Francomb 72), Nathaniel-George (Sesay 64), Grego-Cox, Palmer. Subs not used: Mersin, Poleon, N’Gala.
Referee: Eddie Ilderton.