It was 'nip and tuck' from start to finish and it could have gone either way with never more than a score between the sides right up to the final whistle.
Lymm opened with two penalties from Cormack Nolan before a break by Phil Mills and some good hands creating an overlap opened the way for Jack Ward to go in for his side's first try.
A catch and drive from a penalty line out got Ryan McKibbin over, Ward on hand with the conversion.
Lymm roared back through tries from James Kimber and Adam Bray both converted by Nolan to restore the home sides' lead before an interception of a Lymm attack by George Peel who went in under the posts for a try again converted by Ward made for 20-19 at the interval.
A break by Leon Simpson and neat interplay got Curtis Strong over, the full back coming into the line at pace. Ward added the conversion before trading penalties with Nolan who then went in for a try to make it a one point game, Ward easing Lancashire nerves with a late penalty to seal the win for the visitors.