But their three first half tries from wing James Beale, centre Garin Smith and outside half Mark Cooke, two of which Cooke converted, gave them control of the game.
Hugh Grundy's first half score kept RGC in it and although they managed a penalty try after the break following repeated forward pressure, it wasn't enough.
The victory made it three from three for Cardiff Met and reigning champions Ebbw Vale also made it a hat-trick of wins as they blitzed Narberth 41-3. The home side helped themselves to six tries and were 29-3 ahead at the break.
Sean Jones scored twice for the Steelmen and outside half Carl Meyer kicked 11 points. Other tries came from Ronnie Kynes, Gareth Williams, Gareth Rusby-Davies and Chris Thomas.
The only other unbeaten team moving into the third round of fixtures in the Championship was Pontypool, but they found Llanharan too hot to handle at the Dairy Field where they were beaten 21-6. A penalty in each half by Niall Martin were all the points Pooler could muster, while the home side had a tries from lock Dan Partridge and centre Morgan Williams.
The Llanharan back row shone throughout a tight contest, but once again the goalkicking of outside half Codey Rees proved crucial as he landed three penalties and added a conversion.
Blackwood and Tondu both picked up their first wins of the campaigns. Wing Matthew McGovern led the way for Blackwood in their 34-13 win at Bonymaen as he scored two of his side's five tries.
Fellow wing Rhodri Usher and back row men Jason Jones and David Brake grabbed the other tries and Dan Butler converted three and kicked a penalty. Meanwhile, Ashton Evans scored the crucial second half try that gave Tondu a 20-15 triumph at Bridgend Athletic.
The visitors led 10-3 at the break, but almost lost out to a brace of tries from Athletic wing James Olds in the second half. But a penalty and conversion from Gareth Powell, and a drop goal and conversion from Matthew Murphy, provided the impetus for victory.
Steve Robinson kicked four penalties and converted wing James Davies' try to steer Beddau to a 19-8 home win over Newbridge, while Josh Prosser also bagged 14 points to ad to full back Jordan Purcell's try to give Bargoed a 19-11 win over visiting Tata Steel.