Cardiff were ahead after only four minutes. Good ball from an early line out was spread wide for full back Joe Griffin to cross. The same player added the conversion from a narrow angle.
From the restart Cardiff knocked on, Bedwas retained possession but good defence kept the home side at bay before the home side transgressed and Cardiff cleared to touch. The visitors won the line out but lost possession and Stuart Thomas cleared to touch. Cardiff counter attacked and slick hands put back rower Reuben Tucker in for a try, Griffin again converting. At this stage Cardiff were playing with confidence and fluidity.
Bedwas finally got on the scoreboard courtesy of a long range Powell penalty after Cardiff were adjudged offside on the half way line. This seemed to lift the home side and Bedwas attacked the visitor's line. Bedwas earnt a scrum deep in the Cardiff half and forced the visitors to concede a penalty for collapsing the scrum. Rather than kick for goal Bedwas opted to reset the scrum and this time destroyed the Cardiff scrum and earned a penalty try. Powell added the conversion.
Then came a moment of madness. Powell tackled a Cardiff player late, at worst a yellow card offence. However Powell reacted to something said by an opposing player and was shown a straight red card for violent conduct. Will Thomas stroked over the ensuing penalty goal, but missed a second penalty after Bedwas were penalised for side entry at a ruck.
Replacement Ethan Davies notched a penalty for Bedwas shortly before the break to leave the home side four points adrift for a second half with only 14 men.
It didn't take long for Bedwas to reduce the arrears as Davies added a further penalty after Cardiff were penalised at a ruck. Both sides looked to add to their scores but defences held strong, Bedwas especially to the fore as the home side dug deep.
Bedwas scrum half Tom Rowlands was tackled unfairly 40 metres out and Ethan Davies stepped up to slot the penalty to put ahead for his side in front for the first time in the game; a lead they were not to relinquish.
After a brief delay due to a lack of playing balls Bedwas were on the back foot as Cardiff earned a penalty chance but Thomas was off target before Davies slotted a Bedwas penalty from in front of the posts after Cardiff were penalised at a scrum. Cardiff were not going to lie down and attacked in numbers earning a penalty in front of the posts, this time converted by Thomas.
Bedwas were not finished and five minutes from time delivered the knock out punch. Replacement Matthew Pewtner crossed for a good try after Bedwas attacked a Cardiff line out, Davies added the conversion.
Cardiff desperately sought a losing bonus point and earned a penalty chance but Thomas was wide with his attempt and Bedwas held on for a heroic win.
With neighbours Cross Keys ending the unbeaten run of top of the table Llandovery Bedwas are now top of the Premiership for the first time in their history.
Next Friday (23 November) Bedwas visit Carmarthen Park for a league game against Carmarthen Quins, kick off 7-30pm.