Rhydyfelin's home loss by 42-15 against Nantymoel left them trailing behind the winners and new leaders and second-placed Gilfach Goch in the South-East.
There was a turnup at the bottom as Barry scored a rare and needed win by 28-3 over Tylorstown and Brecon scored a fine win by 25-22 at Nelson and Pentyrch upset Mountain Ash by 14-10.
Cwmbran had a heated match against Abergavenny in the East as three players - two of Cwmbran and one of their opponents - saw red cards but 13-man Cwmbran still pulled off a good 17-10 win with Carl Moore and Ian Hayes scoring tries and Moore converting both and adding a penalty.
Leaders Brynithel and second-placed Llanishen both gained home wins, while in the West Maesteg Quins took advantage of Banwen playing cup rugby by winning 27-10 at Brynamman to go within two points of the leaders. Mumbles pulled off a superb 34-15 win at Glynneath and Kenfig Hill kept up the pressure by defeating Seven Sisters 31-10.
Pontyberem head the West after a 32-3 win at Penclawdd but it was Haverfordwest who moved up to second after a 31-17 beating of Llandybie and Kidwelly did not play. Lampeter beat off a game Pontaddulais effort by 21-12 and Aberystwyth did well to share 18 points at Tenby, while a lone try saw Trimsaran beat Tumble 5-0 and Hendy beat off Gowerton by 25-10.
Pontycymmer pulled off a significant victory in the South-East as they Defeated the leaders Abercwmboi in a tryless match by 9-3 at Lawrence Park with center Andrew Jones and fly half Mike Huntley both dropping goals.
Fairwater took full advantage to move clear at the top of the division after winning 35-10 at Penarth while at the other end of the table Bedlinog secured only their third win of the season by beating Cowbridge 19-15.
Only three games survived in East with Pontllanfraith beating Cardiff HSOB 10-7, second-placed Blaina winning 25-24 at Chepstow, and Monmouth were 63-10 winners at St Josephs.
West leaders Loughor were edged out 14-13 at in-form Burry Port and Pembroke Dock Quins stole a march by defeating second-placed Llanelli Wanderers 20-5. Llandybie had little trouble in dispatching Tycroes 50-10 and Neyland won 44-5 at Bynea.
In South West, Taibach stay one point ahead of Cwmgors after beating Abercrave 34-0 but Cwmgors improved their try tally with a 59-10 rout of visitors Rhigos.
Maesteg Celtic and Glais were locked in a titanic battle with both sides thankful for a point after a 15-15 draw.
Bettws are going to be a difficult side to play against in the East and showed improvement after a 40-14 win over Garndiffaith saw them gain revenge for an earlier loss against the same opponents.
In the South-West there were no surprises as leaders Resolven thrashed Cwmgwrach 78-7 and second-placed Aberavon Green Stars beat Baglan 35-0, while Tonna thrashed bottom club Swansea Uplands by 62-5.
Llandaff stay well ahead in the South-East after beating Canton 34-0 and Ferndale shocked Bridgend Sports Club by 6-5, while Ogmore Vale had a third win of the season when defeating Cilfynydd 22-17.
West leaders Cefneithin are still six points clear of Crymych after a 79-5 win at St Clears while Crymych beat Furnace in a 21-17 away result. Pontyates went mad with a 91-0 beating of bottom club Llanybydder, who have only won twice this season, while Llangwm went down at home to Pembroke by 25-5.
Penygroes were also a club in scoring form as they pounded out a 43-7 home win over St David's.