A youthful Welshpool side paid the price for their inexperience, allowing Menai Bridge to storm to a 27-0 half-time lead that could not be overtaken.
With Menai dominating the early going, it was inevitable they would get the game's first score, a perfectly worked backline move putting them in under the posts. Welshpool's terrible first half continued, with the visitors crossing four more times before half-time.
However, the second half was a different matter, with Welshpool dominating for long periods. After mounting forward pressure, hooker Ryan Griffiths crossed for Welshpool's first score, with scrum-half Ryan Evans adding to Welshpool's tally a few minutes later.
Menai responded with a try of their own, but Welshpool went right back on the attack, with their youth team graduates combining to put Danny Williams over in the corner.
It was the home side who had the last laugh, however, scoring a try almost on the final whistle, and making sure that the visitors could not clinch an important bonus point with a fourth try.
Welshpool: Gwyn Evans, Ryan Griffiths, Ben Aldis, Jamie Evans, Sam Ward, Gareth Gregory, Frank Clifton, Jack Brady, Ryan Evans, Daley Jones, Danny Williams, Andrew Thomas (C), Chay Bowles, John McNicholas, Nick Butler
Replacements: Ben Aldis, Tom Holloway, Wayne Maguire, Barry Williams
Tries: Ryan Griffiths, Ryan Evans, Danny Williams