But Risca, of Division Four East, two divisions below their Division Two West opponents, played well above their level and put in a performance worthy of the famous Millennium Stadium turf.
Ammanford's player/coach Aled Griffiths had words of praise for both Risca and his own young charges, many of who are still eligible to play for the club's youth team.
He said: "We were very impressed with Risca and I felt they played as well as any of the teams in our division."
"It makes me very proud to see that this team, despite of its youth, is so together and plays for each other with so much commitment."
"I am now confident this team can go on and look towards promotion next season, the players are ambitious and winning becomes a habit."
Ammanford opened the scoring on four minutes, with 18-year-old prospect Michael Evans going under the posts for a try which he converted.
It was the first of two tries for the winger, with full-back Cerith Humphries also grabbing a brace, the first of which came midway through the first half.
Evans notched a second converted try with the last move of the half, receiving clever pass from man of the match Chris Jones to run over the Risca tryline.
Leading 19-6 at the break, Ammanford put another ten points on their total in the first ten minutes of the second half after Dylan Cooper touched down in a crowd of bodies, and Gary Stephens used his footballing skills to fully capitalise on a Risca handling error.
With just pride to play for Risca hit back and scored two tries of their own through Tyrone Morris and Dan Dark, with a Ioan Jones try for Ammanford sandwiched between their two scores.
With Risca eager to add a third in stoppage time, the ball broke loose for Humphries who ran the length of the pitch to add Ammanford's seventh to seal a 46-20 win.
Triumphant captain Mark Jones said: "A lot of people wrote us off this season but we've proved we are a good side and I think this win proves it."
Risca backs coach Gareth Evans said: "The boys are disappointed but they didn't let themselves down and we went about the game in the way we like to play."