Ebbw Vale marched to within a win of the Swalec Division One East crown after a comfortable 48-7 win at Rumney.
The Steelmen racked up seven tries as they recorded their 17th win of the season, and have touched down an impressive 90 times in 19 games - 23 more scores than nearest rivals Bargoed.
First-half tries for Ebbw came through flanker Cameron Regan, full back Charlie Simpson and Regan's back row colleague Ronny Kynes, with outside half Dorian Jones adding a conversion and a penalty for a 20-0 interval lead for the visitors.
After the break scrum half Dai Jones, prop Josh Powell and wing Wes Cunliffe crossed the whitewash while Simpson added his second as the Eugene Cross Park side showed the dominance which has carried them all season towards a defence of their title.
Cunliffe's score came after a superb break from replacement outside half Dan Haymond, who also kicked three conversions. Hosts Rumney hold on to eighth place in the table on points difference.
Bargoed stay in contention with Ebbw Vale - at least mathematically - after edging to a 15-14 win over Blackwood at Glan-Yr-Afon.
They must win both their remaining games and hope Ebbw Vale lose all of theirs if they are to have any chance of pipping the Steelmen to the title.
Full back Andrew McLaughlan and flanker Gareth Davies scored the tries for Bargoed as they eked out the narrowest of wins over mid-table Blackwood. Outside half Jeremy Roberts scored a try and kicked three penalties for the home side.
Newbridge came out on top over Gilfach Goch in an entertaining clash between the league's third and fourth-placed sides at the Welfare Ground.
Gilfach led 13-7 at the break, but a three-try burst in the second period from the hosts saw them pick up maximum points for the sixth time this season. Newbridge's tries came through centre Dan Phillips, prop Geraint Weaver and replacements Geraint Langdon and Rhys Price.
In another compelling encounter Beddau left Merthyr with a 32-26 win over the Ironmen. Tries from wing pair Ieaun Coombes and Bradley Coombes, along with flanker Rhys Watkins, centre Lloyd Peart and replacement Abraham Papii secured the points for the Green and Golds.
Elsewhere, Mountain Ash edged a 22-20 victory over the Glamorgan Wanderers at Duffryn Pennar Parc.
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.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series