Crawley were their own worst enemy as captain Danny Brown and then Dave Woozley produced two second-half howlers.
Northwich Victoria reversed a run of four games without a single point with their win as Danny Mayman and Paul Brayson scored their goals after the break.
It was Crawley who were out of the blocks the quickest though with a Tony Scully corner finding Ben Strevens at the near post. His off-balance header was well-directed but unfortunately clattered off the crossbar and out for a goal-kick on seven minutes.
Another Scully corner, minutes later, again caused havoc when this time Ben Judge's delicate near-post flick saw Lee Blackburn attempt the spectacular but his ambitious scissor kick flew wide.
Scott Hiley was then forced to come to Crawley's rescue when Scully gave the ball away cheaply on the halfway line and Mayman's ball over the top found Michael Carr in acres of space but, when he failed to properly control the ball, the veteran defender slid in to intercept.
Despite his defensive failings, Scully was proving Crawley's most potent attacking threat.
He broke down the right-hand side on 24 minutes, skinning Ryan Brown for pace and produced a perfect zipping low cross but no Crawley strikers were on hand to finish.
The final chance of the half fell to Crawley as Brown's hopeful pump up the field found Strevens. He released Scully who in turn found Jake Edwards in space on the corner of the penalty area, but the finish was weak and Northwich keeper Ben Connett gathered comfortably.
Crawley's failure to capitalise on their openings came back to haunt them early in the second half with a shocker from skipper Brown.
His misjudgement in failing to control a long clearance gave Mayman the space to cut inside on his left foot and tuck the ball inside Hamer's far post.
Mayman then peeled off to celebrate in front of the 20 or so Northwich fans who had made the trip south.
Things were to get worse though when Woozley produced his own lesson in how not to defend.
Whether it was the pitch or the driving rain the centre-half had no excuses and nowhere to hide when he allowed a nothing pass to squirm underneath his foot to release Brayson who had a clear run on goal.
The striker wasted no time in rounding Hamer and tapping into an empty net and kill the game off as a contest as early as the 63rd minute.
Crawley boss John Hollins introduced three substitutions in the hope of clawing something back from the game and it nearly paid dividends 15 minutes from time.
Replacements Luke Townsend and Scott Rendell combined but the young striker's right-foot volley flew agonisingly wide with Connett well and truly beaten.
Crawley's lowest attendance of the season then watched in agony as Judge's far-post cross enabled Strevens to leap above the Northwich defence but his header was just too high and dipped over the far post.
In truth Northwich looked comfortable throughout the second half and could have added another when the lively Kevin Townson was introduced with five minutes to go.
His pace proved too much for a lethargic looking Crawley side and Hollins will be grateful they did not fully capitalise on the late flurry of chances they created.
Crawley had one last hooray when Connett punched Scully's lofted free-kick, but as Townsend's attempted lob landed on the roof of the net, it was clear to see where the three points were going.
Northwich Victoria reversed a run of four games without a single point with their win as Danny Mayman and Paul Brayson scored their goals after the break.
It was Crawley who were out of the blocks the quickest though with a Tony Scully corner finding Ben Strevens at the near post. His off-balance header was well-directed but unfortunately clattered off the crossbar and out for a goal-kick on seven minutes.
Another Scully corner, minutes later, again caused havoc when this time Ben Judge's delicate near-post flick saw Lee Blackburn attempt the spectacular but his ambitious scissor kick flew wide.
Scott Hiley was then forced to come to Crawley's rescue when Scully gave the ball away cheaply on the halfway line and Mayman's ball over the top found Michael Carr in acres of space but, when he failed to properly control the ball, the veteran defender slid in to intercept.
Despite his defensive failings, Scully was proving Crawley's most potent attacking threat.
He broke down the right-hand side on 24 minutes, skinning Ryan Brown for pace and produced a perfect zipping low cross but no Crawley strikers were on hand to finish.
The final chance of the half fell to Crawley as Brown's hopeful pump up the field found Strevens. He released Scully who in turn found Jake Edwards in space on the corner of the penalty area, but the finish was weak and Northwich keeper Ben Connett gathered comfortably.
Crawley's failure to capitalise on their openings came back to haunt them early in the second half with a shocker from skipper Brown.
His misjudgement in failing to control a long clearance gave Mayman the space to cut inside on his left foot and tuck the ball inside Hamer's far post.
Mayman then peeled off to celebrate in front of the 20 or so Northwich fans who had made the trip south.
Things were to get worse though when Woozley produced his own lesson in how not to defend.
Whether it was the pitch or the driving rain the centre-half had no excuses and nowhere to hide when he allowed a nothing pass to squirm underneath his foot to release Brayson who had a clear run on goal.
The striker wasted no time in rounding Hamer and tapping into an empty net and kill the game off as a contest as early as the 63rd minute.
Crawley boss John Hollins introduced three substitutions in the hope of clawing something back from the game and it nearly paid dividends 15 minutes from time.
Replacements Luke Townsend and Scott Rendell combined but the young striker's right-foot volley flew agonisingly wide with Connett well and truly beaten.
Crawley's lowest attendance of the season then watched in agony as Judge's far-post cross enabled Strevens to leap above the Northwich defence but his header was just too high and dipped over the far post.
In truth Northwich looked comfortable throughout the second half and could have added another when the lively Kevin Townson was introduced with five minutes to go.
His pace proved too much for a lethargic looking Crawley side and Hollins will be grateful they did not fully capitalise on the late flurry of chances they created.
Crawley had one last hooray when Connett punched Scully's lofted free-kick, but as Townsend's attempted lob landed on the roof of the net, it was clear to see where the three points were going.