Merthyr survived a late onslaught to beat Rhiwbina 29-26 and take home the Swalec Plate at the Millennium Stadium.
A brace of tries from Owen Morgan and further scores from Josh Flye, Osian Davies and Gareth Way sealed a league and cup double for the Ironmen.
Rhiwbina got off to a flying start with tries Brett Chatwin and Sion Summers, but were out-muscled by the Division 1 East champions.
Louis Millar and Chatwin scored late tries to pull the Squirrels back to within three, but Merthyr survived a late scare to take home the Plate.
Rhiwbina stormed into the lead after a well-worked try from wing Chatwin. Outside-half Josh Davies executed a pinpoint cross-kick which found Chatwin, and the Squirrels flyer was too quick for the covering Merthyr defence.
The underdogs stretched their lead after 17 minutes with another score out-wide. The Rhiwbina backs spread the ball to the right flank and Chris Fido offloaded back inside for onrushing full-back Summers to crash over - Gareth McCarthy added the extras.
The Ironmen replied just moments later through full-back Fyle.
The Merthyr forwards tried to shove there way over before releasing the backs who pushed the ball to Fyle.
The full-back dummied his way through the scrambling Rhiwbina defence and touched down to pull his side back to within seven points.
Flanker Davies then found a gap in the opposition defence to complete Merthyr's 12 point comeback.
The back-rower darted through a hole in Cardiff side's defence to score from 10 metres out, fly-half Steve Lang added the extra two points to draw his team level on half-time.
Merthyr, who are a division above their Plate rivals, took the lead after 47 minutes.
The pressure finally told when Morgan squeezed in at the corner following Luke Harwood's offload, taking the score to 17-12.
Morgan scored his second soon after, the lightning winger rounded his opposite man and dived over in the same corner.
Way then crashed over for Merthyr's fifth try to seal the win.
Millar and Chatwin scored late tries to take their team to within three points, but they couldn't get over the line for the winning score.
The annual Women's club launch was held at the Wales Centre of Excellence where National Women's Head Coach and Programme Lead Rhys Edwards, Competition Secretary Adrian Howell and Cardiff Met player Ffion Jones express eagerness for the new campaign to get under way.
Plenty of award winners in this week's Principality Welsh Rugby Union Podcast.Dragons centre Tyler Morgan wins one of the top awards for up and coming talent with the SportingWales Rising Stars 2015 award. Scarlets and Wales outside half Hannah Jones is one of the runners-up. We also he from community clubs as the season approaches and Principality Premiership unsung hero Ron Taylor of Ebbw Vale.
Actor and Millennium Stadium Tour Guide Gareth Bale has been performing his one-man play about Wales rugby legend Ray Gravell across Wales. He chats to WRU TV before taking his show to the Edinburgh Festival.
After widespread consultation, the WRU has made major changes to its pathway programme for girls rugby with a spring and summer season being introduced with immediate effect in order to respond to a clear demand to play the game.
The Webb Ellis Cup visited Lampeter on Monday to recognise the fact that the town is celebrating a major milestone as it is believed the first ever game of rugby played in Wales, was in fact played in Lampeter 150 years ago.
We cover the big news the 2017 Champions League Final will be coming to the Millennium Stadium, in this week's Principality Welsh Rugby Union Podcast. We hear from FAW chief executive Jonathan Ford, First Minister Carwyn Jones and WRU group chief executive Roger Lewis. Wales coach Warren Gatland describes their high altitude training in Switzerland, national match officials manager Nigel Whitehouse talks about the community coaches and referees conference, while we have a special feature on Cardiff Blues U18 girls sevens squad preparing for their first Gemau Cymru, with some help from internationals Elinor Snowsill and Philippa Tuttiett.
Cardiff Blues U18 Girls will go into Sunday's Gemau Cymru with an extra spring in their step after Welsh internationals Elinor Snowsill and Philippa Tuttiett offered some last minute tips at a training session earlier this week.
Rob Howley and Josh Lewsey addressed more than 250 community club coaches and referees at the first WRU National Community Conference on the weekend. The volunteers benefitted from coaching masterclasses and workshops in a bid to connect all levels of the rugby pathway in Wales.
The winners of a filmmaking competition organised by the education charity Into Film and the WRU enjoyed a behind the scenes tour of the Millennium Stadium - and a chance to be photographed with the WRU's fire-breathing, rugby loving mascot, Scorch The Dragon, and Welsh international, Jake Ball.
Ebbw Vale coach Jason Strange is proud of his side's effort in against Pontypridd in the Principality Premiership final and as WRU TV's Liz Jones finds out, he's now looking forward to Wales' Under 20 campaign with confidence.
Principality Building Society has joined forces with the Welsh Rugby Union to offer every club in Wales the opportunity to reward their most cherished volunteers with tickets for Wales' Dove Men Test clash with Italy at the Millennium Stadium next weekend, Saturday 5th September 2015 (5.00pm).
A day of entertainment is promised during the Foster's National 7s at the BT Sport Cardiff Arms Park on Sunday 30 August, with games, fancy dress prizes and festive food and drink on offer as an added bonus alongside some fast and furious rugby.
Developing the game in Wales and creating a stable and progressive environment for players of the future
Taking the grass roots game out across the length and breadth of the nation, the SWALEC Leagues are the focus of the community rugby in Wales
SSE SWALEC Cup
The SSE SWALEC Cup, Plate and Bowl continue the legacy of the WRU Challenge Cup, culminating in a shot at glory at the Millennium Stadium
Women's Community Rugby embraces both the regional and community club game from Girls' Leagues through to the Women's Premier Division