Both sides enjoyed life in the top division before dropping through the leagues, but the Zebras are currently enjoying a revival and are in second spot in SWALEC League Two East.
Maesteg, meanwhile, are top of Two West, which means the game at The Oval is likely to be a close run contest.
Two East leaders Gilfach Goch won at Tylorstown of Three South East in the last round and now have home advantage against another Three South East side in Llandaff North.
Ammanford, of Two West, disposed of Llanelli Wanderers and Morriston in the earlier rounds and their prize is a home clash with Loughor from the same division.
Loughor won 25-22 when the sides met at Ammanford in the league earlier in the season.
SWALEC PLATE Round Three draw
(Ties to be played weekend of 16 January, 2010)
Ammanford v Loughor
Bryncoch v Aberavon Quins
Brynmawr v Tredegar Ironsides
Crymych v Laugharne
Gilfach Goch v Llandaff North
Gwernyfed v Garndiffaith
Kenfig Hill v Tondu
Llantwit Fardre v Pentyrch
Mumbles v Waunarlwydd
Nant Conwy v Caernarfon
Newcastle Emlyn v Aberystwyth
Penarth v Aberdare
Rhydyfelin v Penallta
Ruthin v Denbigh
Skewen v Glynneath
Treorchy v Maesteg
