Risca fared a little better after winning 31-26 at Penarth when they were given a home tie against the winners of Nant Conwy and SWALEC One North leaders Caernarfon.
Ammanford of SWALEC Two West were too strong for Penclawdd with a 21-3 third round victory, and they will be home again, this time to the winners of the Kidwelly/Llanelli Wanderers tie.
Newport HSOB shocked Pill Harriers by winning a close derby encounter 10-3 and they will play host to the winners of BP Llandarcy and Glynneath.
SWALEC Plate Round Four
Ties to be played the weekend of 19 February, 2011
Brecon / Tylorstown v Skewen / Bryncoch
Ammanford v Kidwelly / Llanelli Wanderers
Aberystwyth / Pontyberem v Pontypool Utd / Brynmawr
Ruthin / Mold v Aberdare
Risca v Nant Conwy / Caernarfon
Tondu / Heol y Cyw v Llantwit Fardre / Mountain Ash
Loughor / Gorseinon v Rhymney / Penallta
Newport HSOB v BP Llandarcy / Glynneath
