The early part of the game followed a familiar pattern as Garstang came flying out of the blocks before letting the opposition back into the game.
With just a minute or so played Garstang were camped on the try line and Charlie Clark ghosted through the defence to score under the posts.
Minutes later the lead was extended as Clark put a raking kick into the corner which Ian Makinson raced onto and touched down before a Clark penalty made it 15-0.
The visitors put in a massive effort and got their reward with a pair of tries midway through the half to change the complex of the game amd trail 15-12.
Garstang were stuttering at this point but, in the minutes leading up to the break, they managed a couple of well worked tries.
Man of the match Adam Riley was tackled just short of the line but managed to scramble over and touch down.
From the restart Ben Kelsall took the ball at full tilt and rampaged through the defence before he offloaded to Lawson Whittaker.
The ball was quickly recycled and passed to Joel Dugdale, who touched down under the posts to give Garstang a fourth try, a bonus point and a 29-12 half-time lead.
A Clark penalty made it 32-12 early in the second half before Garstang relaxed and scored a trio of well executed tries through Gavin Barton, Riley and Andy Tissingh.
The win sees Garstang top of the table, five points ahead of Ormskirk and Clitheroe.
The seconds lost 25-7 to Blackpool in their top-of-the-table clash.
On Saturday both teams are away with the firsts at Eagle and the seconds at Colne & Nelson (both 3pm).