ALED Hamilton was the hero with two tries as Machynlleth edged a semi final first-leg over plucky Harlech.
The inside centre finally broke their resolve on 33 minutes, with Iwan Jones converting.
Hamilton added a second try after the break and although Jones missed the conversion he added a penalty to ensure Machynlleth a first-leg advantage.
The winners will take on Newtown or Abergele in the final.
MACHYNLLETH: Thompson, H Griffiths, D Jones, A Lloyd, McAuley, M Davies, D Lloyd, Lewis, Blockley, I Jones, Morris, J Davies, Sandy, A Jones, H Griffiths. Reps - R Morris, Nicholas, Bracher, J Jones, Vaughan