Langdon further extended the home advantage with a penalty from distance before Bedwas replied with a penalty from outside half Ethan Davies.
Kevin James then put Neath further ahead with Scott Williams replying for Bedwas. Chris Morgans then touched down for the bonus point try in first-half injury time to give Neath a convincing half-time lead of 31-10.
Neath knew they couldn't rest on their laurels though and it was Bedwas who got the second half off to a flyer with scores from Josh Davies and Ethan Davies, the latter converting both to bring the visitors to within seven points.
Neath were not to be denied though and further tries from Kevin James and captain Gareth Gravell put gloss on the scoreline. Both were converted by Dai Langdon who kicked all seven of his attempts at goal.
Ethan Davies kicked a penalty just before Gravell's try to give the visitors hope of a losing bonus point but it was not to be.