Garstang lost top spot in the West Lancashire League Premier Division following defeat on Tuesday night and victory for Blackpool Wren Rovers.
After extensive sanding the Riverside pitch passed an inspection and Garstang almost took the lead after five minutes.
Ric Coar had an effort well saved following good work from brother Alan and Matt Poole before seeing another header saved low down.
However, against the run of play, Haslingden attacked down the left in the sixth minute and Lewis Hanley cut inside before hitting a low cross-cum-shot which ended up in the net.
Further chances came and went as Garstang missed a number of clear goalscoring opportunities.
These misses would prove costly as Haslingden doubled their lead on 18 minutes when they broke quickly with Alex White getting behind Tom Graham to fire a shot across the keeper and into the net.
The scoreline did not reflect the balance of play but the second Haslingden goal pushed Garstang into another gear.
Tom Entwistle reduced the deficit with a 25-yard screamer into the top corner and, as the game approached half-time, the scores were levelled.
Ric Coar was cynically fouled when through on goal, giving Garstang a penalty which Entwistle calmly converted to make it 2-2 at half-time.
The second half continued in the same manner as the first with Garstang missing chance after chance through a combination of resolute defending, good goalkeeping and poor finishing.
They continued to have much of the play but it looked like being one of those games where nothing was going to go into the net.
This proved to be the case and, to make matters worse, a rare counter-attack with 14 minutes left brought the winner when Hanley’s shot was deflected and looped into the Garstang net.
With all three substitutes on Garstang did everything possible in the remaining minutes to equalise but ran out of time.
The Riversiders will look to get back to winning ways when Whitehaven visit them on Saturday (3pm).