Cross Keys winger Jason Williams produced the individual performance of the day with six penalty goals - a club record - in his side's 18-16 victory over Newport at Rodney Parade. Newport scored the only try of the match through centre Will Kershaw-Naylor, but Williams' kicking ensured Cross Keys move above their rivals in the table.
Pontypridd cemented third place on the table with a comfortable 33-11 win at Bedwas, with scrum-half Wayne Evans leading the way with a brace of tries.
Second-placed Bridgend had to fight every inch of the way before securing a 13-10 win at Maesteg. Bridgend's Ryan Howells scored a crucial second-half try and outside-half Gareth David's two penalty goals proved the difference between the two sides. Prolific backrower Karl Hocking bagged the home team's only try.
Llandovery proved too good for Carmarthen Quins, winning 34-13 to consign Quins to the bottom of the Premiership table. Outside-half Gareth Morgan scored a try and kicked 19 points in a man-of-the-match performance. Centre Darren Simpson scored Quins' only try.
Struggling Ebbw Vale secured three valuable points with an impressive 27-14 win at Pontypool. The Steelmen scored five tries to two and took a match-winning 22-7 lead into the break.
In Division One matches on Boxing Day, Blackwood returned from Caerphilly with a 20-17 victory, while Llangennech beat Whitland 15-7.
Bedwas 33 Pontypridd 11
Carmarthen Quins 13 Llandovery 34
Maesteg 10 Bridgend 13
Neath 31 Aberavon 23
Newport 16 Cross Keys 18
Pontypool 14 Ebbw Vale 27
Caerphilly 17 Blackwood 20
Llangennech 15 Whitland 7