The leaders took a while to get into their stride, then raced clear by scoring six tries with fly half Mark David gaining a try, five conversions and a penalty goal, while skipper Karl Hocking notched his 116th league try.
The Old Parish also ran in tries by flanker Marcus Sainsbury, wing Gareth John, centre Alun Brown and wing Gareth Holmes, while fly half and skipper Stuart Morris placed three penalty goals for the Athletic in a game well controlled by Clayton Thomas.
Glamorgan Wanderers remained in third place despite beating UWIC 36-12, but are now just one point behind Llangennech with a game still in hand and a better try-count.
No 8 Emyr Christopher had an outstanding game and he, Mark Heywood, Dave Willey, Lee Mullane and replacement scrum half Gareth Spain went over with Heywood converting one and landing two penalties and Jason Pocock also placed a penalty.
The students ran in tries by Rhys Edwards and Gareth Dacey and Phil Dolman converted one.
Blackwood battled their way to a 25- home win over Builth Wells and went out of therelgation zone, moving over Fleur de Lys, Carmarthen Athletic and UWIC in the process.
Fly half Jeremy Lloyd led the way with a penalty, drop goal and two conversions and tries came from Jamie Sims (2) and Christian Perry, while Rob Lloyd placed a lone penalty for Builth Wells.
Bonymaen jumped from seveth to fifth place after a 30-0 win over Tonmawr, who now are staring relegation in the face and have eight game to survive, but are already 13 points away from safety.
Scrum half Gareth James, formerly of Penygraig, notched four of the five tries by the Parc Mawr club and wing Chris Griffiths also crossed with Anthony Evans placing a penalty and conversion.
The Webb Ellis Cup visited Lampeter on Monday to recognise the fact that the town is celebrating a major milestone as it is believed the first ever game of rugby played in Wales, was in fact played in Lampeter 150 years ago.
Cardiff Blues U18 Girls will go into Sunday's Gemau Cymru with an extra spring in their step after Welsh internationals Elinor Snowsill and Philippa Tuttiett offered some last minute tips at a training session earlier this week.
Rob Howley and Josh Lewsey addressed more than 250 community club coaches and referees at the first WRU National Community Conference on the weekend. The volunteers benefitted from coaching masterclasses and workshops in a bid to connect all levels of the rugby pathway in Wales.
UEFA has today confirmed the Football Association of Wales (FAW) has been successful in its bid for the Millennium Stadium to host the 2017 UEFA Champions League Final on Saturday 3rd June, 2017 (kick-off: 19.45hrs GMT).