Llanharan have a tough task to stay at the top of One East when they travel to Virginia Park to take on a Caerphilly side only three points behind them in the table.
The Dairymen could be overtaken by Merthyr, who visit a Penallta outfit still smarting from their heavy defeat last week, or by Newbridge who entertain Rumney.
Bottom-placed clubs Newport Saracens and Ystrad Rhondda meet with the losers left stranded at the foot of the division.
Four clubs are making the pace in One West with leaders Carmarthen Quins hoping to maintain their three point advantage over Tonmawr by beating visitors Felinfoel. The high-scoring Tonmawr outfit, who have played a game less than Quins, play host to Bonymaen while Narberth travel to Maesteg.
The Otters have already bagged 23 tries in their four matches to date but cannot afford to slip as Whitland are unbeaten, only two points behind, and will relish the visit of Carmarthen Athletic who conceded 12 tries on their last away outing.
Treherbert will be looking for points in their trip to Fleur de Lys in Two East. After three matches they have yet to open their account while Fleur already have a victory in the bag. Leaders Llantrisant are at Abergavenny who have lost three times this season so the Black Army should remain in pole position.
Penclawdd have a tough trip to Builth Wells as the Two West leaders have won all four matches this season, but the Cocklemen have won away from home so will not be overawed at meeting the Bulls. There is a bottom-of-the-table clash at Pencoed where the home side entertain Gorseinon with only try count separating the teams.
Rhymney have a tough task in Three East when leaders Gwernyfed visit War Memorial Park. The Brewers have lost both opening matches conceding over 70 points while Gwernyfed are a point ahead at the top of the table. Nelson are handily placed to take advantage of any slip-up against Rhymney and they are home to a New Tredegar side with one bonus point keeping them off the bottom.
Pontyberem have gained maximum points from their first four matches and are already six points ahead of second-placed Cardigan in Three West. They take that record to Lampeter while Cardigan visit bottom club Llanybydder. Aberystwyth are also unbeaten but have played only three games. They entertain a Tumble side that were soundly beaten last time out.
Four clubs are within two points in Four East and it could be all change after the weekend. Leaders Llandaff take on the Squirrels of Rhiwbina in an all-Cardiff clash at Bishop's Field while Monmouth and Machen will hope to keep their unbeaten records against Crumlin and Tredegar Ironsides respectively.
Top plays bottom in Four West where leaders Brynamman play host to Cwmgors. Four clubs are on ten points and two of them, Trimsaran and Tycroes, play each other while Betws visit Tenby and Hendy are at unbeaten Llandeilo.
Abercarn are two points clear at the top of Five East and they entertain Blaenavon while Oakdale, three wins from three outings, put their unbeaten record on the line against Usk.
Swansea Uplands are without a point in Five West and they travel to Milford to play the Mariners who have won their opening three fixtures. Leaders Cefneithen play host to an Aberaeron side that recorded their first victory last weekend.
It was a double celebration for Wales and Ospreys scrum-half Rhys Webb when he called at the home of Welsh rugby to help commemorate the first anniversary of Principality Stadium and his return to fitness this weekend ahead of the RBS 6 Nations.
Prior to their departure to Wellington for the next leg of the World Series, Wales trained with England and Ireland. WRU TV caught up with Owen Jenkins who revealed the 'buzzword' which is driving the Wales squad on.
Wales head coach Rob Howley explains his decision to change the captaincy of the national side with Ospreys second row Alun Wyn Jones taking over from Sam Warburton for the forthcoming RBS 6 Nations. Howley is hoping his decision will allow Warburton to rediscover his 'mojo'.
How do you follow a dancing hippopotamus - the Ospreys wheelchair rugby team has just the 'oneness' to do it say the BBC! For a decade the sight of a herd of hippos synchronised swimming around their own private blue lagoon, has lit up our television screens at regular intervals between favourite BBC One shows. But now the nation's most watched channel has relinquished its famous amphibious mammals in favour of a new show-reel which includes the Ospreys wheelchair rugby team.
Head coach Rowland Phillips and key front rower Carys Phillips look ahead to games against Spain and Ireland as Wales Women ramp up their preparations for the forthcoming Six Nations. The two warm-up games are a 'massive opportunity to refine the squad' according to the Welsh camp.
Martyn Phillips has discussed details of the newly published 'Strategy for Welsh Rugby' which puts in black and white terms the plans and direction of the governing body of the national sport in Wales for the next decade.
WRU chief executive Martyn Phillips has urged Welsh rugby fans to follow in the footsteps of their soccer counterparts at last summer's Euro Championship by backing their team to the hilt in the upcoming RBS 6 Nations campaign.
Chief executive Martyn Phillips has highlighted the plans for Wales to become a breeding ground for national and elite club rugby coaches, which are contained in the WRU's 10-year 'Strategy for Welsh Rugby'.
Andrew Coombs is enjoying his new role as Nelson forwards coach. The former Dragons and Wales lock has big ambitions to become a professional coach but feels it's important to learn the ropes in grassroots rugby and where better than his home club Nelson, with friends and family close to hand.
Students at Brynllywarch Hall School, near Newtown, have transformed their own lives, and are now having a positive impact on others through rugby. The sport has had a life-changing effect on the well-being of the students who are now delivering rugby sessions to local primary schools and playing for a new mixed ability side
Wales reached their first semi-final since 2013 in the opening round of this season's HSBC World Rugby Sevens Series in Dubai. WRU TV's Graeme Gillespie recaps on what proved to be an eventful tournament
Wales and Ospreys back row James King, who came through the North Wales age grade system, nominated North Wales Regional Community Rugby Manager Marc Roberts, in the WRU's 'Diolch' initiative where squad players thanked those who played a part in their rise to the top.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.