Cardiff made it a quickfire double over their near neighbours as they rattled up five tries without reply in the first-half to continue their good end to the season.
Having beaten Caerphilly 38-8 at the Arms Park eight days earlier, they matched that tally in the opening 40 minutes to pile on the points and consolidate their fourth place in the Welsh Premiership.
It was Wales full back Rhys Williams who started the early flourish as he ran in a solo try after 18 minutes. By the interval Dean Dewdney, Adam Jones, Don van Vuuren and Ryan Powell had followed suit.
It was not the kind of start that former Cardiff and Wales great Mark
Ring had been hoping for from his home side, especially as they have a major European final to come in two weeks time when they face Castres in the Parker Pen Shield final in Reading.
Things went from bad to worse shortly after the break when Wales utility back Iestyn Harris hoisted his match tally to 20 points with a try and a sixth conversion to further stretch the lead.
But far from throw in the towel, Caerphilly rallied and two more penalties from outside half Luke Richards gave them new hope. Then two tries in the space of four minutes, both converted by Richards, breathed new life into the final quarter.
Wing Ryan Howells crossed for the first of the home tries and then lock Darren Davies romped over moments after his opposite number Heino Senekal was sent to the sin-bin. But all that was left in the game were two more penalties from the two outside halves and Cardiff hung on for victory.
Caerphilly: Tries: R Howells, D Davies; Cons: L Richards 2; Pens: L Richards 6.
Cardiff: Tries: R Williams, D Dewdney, A Jones, D
van Vuuren, R Powell, I Harris; Cons: I Harris 6; Pens: I Harris 2.
Wales Under 18 captain Callum Bradbury is delighted to have seen his side claim a narrow 18-17 victory against a strong SA Schools 'A' side to end the three-match Under 19 International Series in South Africa on a high note.
The Wales U18 squad spent an emotional day in the drug-riddled townnship of Hout Bay. Hout Bay Warriors President Fred Johannes said the visit was 'the talk of the town' and will dream about the day everyday for the rest of his life.
RGC 1404's new head coach Mark Jones is hoping to build 'something special' in north Wales and is already looking forward to the development region participating in the Principality Premiership for the very first time.
A joint venture between the WRU and Admiral saw hundreds of children enjoy the Admiral Festival of Rugby held at the National Centre of Excellence at the weekend where Welsh internationals Sam Warburton, Scott Williams and Rob Evans were in attendance.
Wll Jones leads Wales U18s into battle this afternoon against Italy where the Welsh side will be seeking to bounce back from their narrow defeat to SA Schools in their opening clash of the U19 International Series
All four regions attended a successful training camp staged last weekend at the WRU National Centre of Excellence. It was a chance for new Wales Women's head coach Rowland Phillips to deliver his key messages to players and coaches as he prepares for the new season.
Wales U18 Team Manager Gethin Watts believes the next couple of weeks will be 'extremely beneficial' to the future of Welsh rugby as his side prepare to take part in the Under 19 International Series being staged in South Africa.
The WRU is searching for 12 new rugby development apprentices following a successful first year of its WRU Coach Core programme. Craig Duncan and Jess Hancock have flourished in the first year of the programme which has given them a real direction in their lives.
The WRU signed TV comedian Rhod Gilbert up to a 'Coaching Children Level 1' course before letting him loose on an U8s side at Whitland Junior Borderers - we went behind the scenes to film the making of 'Rhod Gilbert's Work Experience' see the results here.
Llandovery are aiming to make it three titles in a row in this year's Foster's National 7s being held at BT Sport Cardiff Arms Park on Sunday 28 August. Drovers assistant coach Simon Davies and Lee Rees assess their sides chances
A pioneering strength and conditioning programme has been delivered to more than 8000 boys and girls at hub schools throughout Wales this season, helping to develop stronger, more flexible athletes for rugby and other sports.
The Singha Premiership Rugby 7s Series returns to the BT Sport Cardiff Arms Park on July 22nd when all four Welsh regions go head to head. Scarlets skills coach Dai Flanagan and Blues Elite Performance Pathway Manager Richard Hodges along with current Welsh squad members were at the launch of this season's event