Llandudno's 15 tries included seven from there centre pairing of Lloyd Owen, who ran in four tries, and David Davies who scored a hat-trick.
It was a family affair for Cardigan, as brothers Guto and Iestyn Crompton were both on the scoresheet as the home side beat Pwllheli 22-21.
Guto crossed twice whilst Iestyn, as well as converting both tries, kicked the winning penalty five minutes from the end.
Penygroes saw the try count rule work in their favour as they advanced after drawing 14-14 with Aberavon Green Stars.
Billy Lewis and Darren Price crossed in either half for Penygroes, meaning they won the game 2-1 on tries despite a Green Stars comeback.
Birchgrove of squeezed through to the third round after a narrowly beating Amman United 25-21.
Lee Mainwaring scored 20 of the home sides 25 points, in the form of 2 tries, 2 penalties and 2 conversions.
Hendy won a Llanelli derby at Furnace 19-15. Emyr Harris went over for their only try which was converted by Lee Evans, who also kicked four penalties.
Tredegar are the team on everyone's lips so far in the Swalec Cup after racking up 146 points and 22 tries in the opening two rounds.
Their 56-10 victory against Cwmgwrach came after their club record 90-0 win against Pontllanfraith in the first round. Greg Jones grabbed a 21 point haul from a try and eight conversions while Jamie Henthorn and Chris James each claimed two tries a piece.
Division Five South-East outfit Cowbridge pulled of the shock of the second round, defeating Mumbles 16-10. Despite the three division gap between the clubs, two second half penalties from Ed Lakin sealed an unlikely victory after the sides had gone into the break at 10-10.
Talywain stunned a Nantymoel side placed two divisions above them in a 27-5 triumph with Gareth Needs scoring two of his side's four tries at Emlyn Park. In other second round upsets, Division Four Monmouth overcame Seven Sisters of Division Three 34-17, and Aberavon Quins beat Abergavenny 5-3 thanks to an early try from left-wing Adam Dawe.
Bedlinog were the big scorers of the second round after they scored 11 tries in a 71-0 mauling of Llanidloes. Thomas Cox and Lee Harrison each grabbed a hat-trick of tries for The Foxes.