In a match played during increasingly heavy conditions, eventually the superior strength of the Quins' pack booked the visitors a place in the next round of the Naylor Drainage Cup.
Outside-half Richard Morris gave the Athletic team the lead with a penalty, but Quins captain and lock forward Gary Evans crossed for an unconverted try.
In the second half, Quins scrum-half Gareth Jones crossed for a try to extend the lead and was also successful with two penalty attempts.
The Athletic team stuck at their task and for most of the game the defensive work by the pack near to the Narberth line against the bigger Quins pack kept the visitors at bay.
Number eight Alec Hill was nominated the Narberth man-of-the-match.
Post-match
presentations at Narberth
In the post-match presentation ceremonies following the Division One match between Narberth and Llangennech, popular Narberth prop Alan Phillips received an award from club chairman John Williams for notching up over 100 league appearances for the Otters.
In addition, supporters' club chairman Geoff Morgan also presented the player with a memento on behalf of the club's supporters.
In another presentation, Keith Bailie, proprietor of the Milton Brewery, Milton, presented two Otters to club chairman John Williams. One Otter had been caught at Meidrim Brook in 1925 and the other at Blackpool Mill in 1930.
Mr Bailie has been proprietor of Milton Brewery for approximately 18 months, having previously been the catering manager at Lord's Cricket Ground.