Llanidloes really paid the penalty at Ruthin, squandering a chance to get back in the game from a spot kick.
Ruthin led the JD Cymru North fixture 1-0 after Daniel Cox gave them a 35th minute lead but Connor Bird had the chance to level the scores but missed his 58th minute penalty.
And three minutes later Will Owen punished the Daffs, making the final score 2-0.
Llanfair crushed Kerry 5-0 in the Lock Stock Ardal North East League with braces from Max McLaughlin and Astley after Griffiths had given the home side an early lead.
Results were
Bernie Jones Memorial Trophy Final
Trefonen 2 Trewern United 1
Saturday
JD Cymru North
Llangefni Town 0 Guilsfield 3
Ruthin Town 2 Llanidloes Town 0
Airbus UK 5 Llanrhaeadr 1
Lock Stock Ardal North East
Carno 0 Penparcau 4
Llanfair United 5 Kerry 0
Penycae 2 Four Crosses 1
MMP Mid Wales League East
Llanfyllin Town 3 Bishop’s Castle 3