Crawley paid the price for some wasteful finishing as their seven match unbeaten league run came to an end at Gillingham.
Billy Clarke and Jamie Proctor spurned gilt-edged chances while Joe Walsh also headed against the post as Reds failed to score for only the second time in a league game under John Gregory.
Gillingham also had their chances but were denied by some fine saves by Paul Jones before substitute Charlie Lee grabbed a winner with two minutes to go.
The result saw Crawley slip to 16th in League One and put a huge dent in their outside hopes of challenging for the play-offs.
The first half was a scrappy affair but both sides had excellent chances to break the deadlock.
Billy Clarke should have given Reds the lead after 15 minutes when a cross from Mike Jones looped up to him at the far post off a defender but his volley went wide.
Neither side seemed able to string any passes together and it was no surprise that Gillingham’s best opportunity came from a set-piece.
Paul Jones failed to get any distance on his punch from Jake Hessenthaler’s corner and with the Reds keeper still out of his goal Joe Pigott fired wastefully over from ten yards.
Jamie Proctor, recalled to the starting line-up after an impressive performance off the bench against Stevenage, then squandered two promising openings as Crawley finished the half strongly.
First Proctor’s shot was deflected just wide with Matt Tubbs close to diverting it in at the far post and then the striker took too long to pull the trigger after cutting in from the left and his shot was blocked.
Pigott had a second sight of goal just before the interval when he fired over following another unconvincing punch by Paul Jones.
The chances kept coming thick and fast in the second half but neither side were able to take advantage.
Tubbs shot over from 18 yards while Billy Clarke had an effort superbly blocked by Adam Barrett while at the other end Paul Jones saved from Pigott twice and also kept out shots from Craig Fagan and Cody McDonald.
Crawley should have broken the deadlock with 20 minutes to go when Proctor somehow skied his shot from five yards after being teed up by Mike Jones’s cut back.
Reds went even closer in the 85th minute when Joe Walsh headed against a post from a corner and then when the ball was played back in by Dannie Bulman, Clarke somehow headed wide from three yards.
It proved costly as Gillingham went up the other end to score the decisive goal. Leon Legge headed a corner back across goal and it fell to substitute Lee to bundle home from six yards.
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