In an entertaining encounter, it was the home side who edged it with a 23-21 victory enough to see them through to the quarter finals.
Bedwas were forced into a late change with Stuart Thomas arriving just before kick off with Ethan Davies taking over full back duties and Thomas dropping to the bench.
The game started at a furious pace with Bedwas on the back foot as the Quins were quickly into their stride. It came as a surprise then that Bedwas would score the first try after five minutes, the ball worked right for Rory Budina to score a fine try with Lewis Robling adding the conversion.
Carmarthen regrouped and kept Bedwas on the back foot before levelling the scores with a penalty try after the Bedwas scrum was shunted backwards. Jack Maynard added the conversion.
The visitors regained the lead after 24 minutes when Deri Mattravers ran through for a superb individual try with Robling again adding the conversion. The Quins continued to press but the Bedwas defence held firm though they were undone two minutes before the break when prop Rob Evans was on the end of a flowing move to cross for a try.
Maynard again made no mistake with his conversion attempt and it got worse for Bedwas as Dan Preece was sin binned for tackling a Carmarthen player off the ball in the build up to the try.
The second half started much as the first had ended with Carmarthen having the lion’s share of possession and territory. And they took the lead for the first time via a penalty from Maynard after Bedwas were adjudged off side.
Bedwas were not looking like lying down and stormed back into the lead. With the referee playing a penalty advantage, scrum half Tom Rowlands kept the ball alive and Mattravers crossed for his second try of the afternoon, Robling again converting.
Maynard saw a penalty attempt hit a post but was on target with his next attempt after Bedwas were penalised at a ruck, Phil Sargent sin binned by referee Nigel Owens for hands in the ruck.
And Bedwas were unable to hang on to their one point margin with Maynard delivering the knock out blow minutes from time – his penalty securing the win.