But the race for the title is still very much wide open as reigning champions Pwllheli have two games in hand in second place and have only lost once all season. Third place Caernarfon are 14 points behind the leaders.
Nant got off to a flying start with two tries in the opening six minutes to take firm control of the game. Delwyn Jones crossed for the first and Carwyn Davies followed suit three minutes later. Jones converted both to make it 14-0.
Ruthin battled back with a try from Tom Seddon, converted by Nathan Jones, but it was 33-7 by the break as Nant clinched their bonus point with further tries from Ifan Hughes, Sion Pringle and Cai Jones. Delwyn Jones converted the last two.
The second half was pretty even as each side scored a try each. Ryan Roberts crossed for the visitors just after the hour before Ifan Pyrs crossed for the sixth home try to round off the scoring. In the other game in the North, Bro Ffestiniog comfortably beat bottom of the table Abergele 43-8 to leave their visitors still waiting for their first win of the campaign.
In Division 1 West, Whitland made it three wins in a row with a 14-6 triumph at Felinfoel that continued their march our of the relegation zone. They added the scalp of the mid-table side to those of Aberystwyth and Penclawdd earlier in the month to move into 10th place, six points clear of bottom of the table Gowerton.
Bridgend Athletic closed the gap on league leaders Bonymaen to a single point with a 21-6 home win over Ammanford, but they have played two more games than the leaders.
