Big match in the West will be at Pontyberem, where unbeaten Haverfordwest are the visitors. Both clubs are on 39 points and with them are Kidwelly, who travel to Tenby.
In the South-East there will be a close match between Gilfach Goch and Rhydyfelin, with Nantymoel at home to Ynysybwl and Treherbert trying to halt their surprising slump with a win at Tonyrefail.
Banwen top the South-West by five points and have a match away to Trebanos, a basement club, who are suddenly picking up. Pick of the division could be Kenfig Hill against Bryncoch and Nantryffyllon's match at Mumbles.
In the East, leaders Brynithel are away to bottom club Llanhilleth, but the match of the day could be at Cwmbran, where Llanishen will provide the opposition.
Matches in Division Four will come no bigger than that in the East at Central Park, where second-placed Blaina take on leaders Bargoed with the home side having a game in hand, but trailing by eight points. Bargoed have won all their 14 much thus far.
West leaders Loughor entertain Betws, while Llanelli Wanderers travel to Fishguard and the top match may be at Laugharne, where fast-rising Pembroke Dock Quins are the visitors.
Abercwmboi against Aberdare could provide a good match in the South-East, where Fairwater have a tough one against Pontycymmer and Old Penarthians take on neighbours Penarth in a basement duel.
Alltwen's match with Cwmgors is the top one in the South-West. Leaders Taibach are at Pyle and improving Briton Ferry go to Glais.
Ruthin should hold therir lead in the North as they go to Bala with Nant Conwy at Llandudno and Caernarfon go to Wrexham in search of three points.
Cefneithin will stay ahead in the West, even if they were to be shocked by Furnace, while Crymych visit New Dock Stars. In the East only five matches are scheduled with Trinant taking a six-point lead to Usk.
Llantwit Major have a must-win home match against leaders Llandaff in the South-East and in the South-West, leaders Resolven travel to bottom club Swansea Uplands.
In the North. leaders Denbigh entertain Welshpool and Colwyn Bay have a home match against Bangor.