Risca booked their place in the semi-finals of the SWALEC Plate after ending Cardiff University's cup dream with a thrilling 48-28 victory.
Risca are now the lowest-ranked side left in the competition, but will surely fancy their chances after a stunning eight try haul.
Tries from Rhys Putter and Rhys Carpenter and David Jefferson helped the home side on their way to a 26-14 half-time lead, but it was in the second period that Risca really turned on the style.
Two tries from number 8 Richard Evans and a try each from Nicky Davies, Owen Cooper and Tim Barnes completed the rout, although the students of Cardiff went down fighting and can be proud of their displays in this season's competition.
Tredegar Ironsides pulled off the shock of the day with a 15-0 win over Nantyffyllon. The Division Four East outfit grabbed a try in each half through wing Lewis Pritheroe and centre Craig Monaghan.
Rhydefelin survived a second-half comeback from fellow Division Two East side Mountain Ash to win 21-15 at Parc Duffryn Pennar.
The away side had lead 15-5 at half-time thanks to two tries from Aled Jones, before tries from centre Adrian Owen and Dale Keppin hauled Mountain Ash back into the game.
Two penalties from Geraint Watts kept the home side at bay to ensure Rhydyfelin's passage into the final four.
In the remaining quarter-final game Ammanford ran in three tries as they beat Newcastle Emlyn 28-15.
The Welsh Rugby Union is forming a new Youth Board with a brief to help keep more young people involved in the game during their late teenage years and beyond. The first task of the fifteen strong Board will be to analyse and consider the issues which lead to a number of youngsters drifting away from the sport between the ages of 16 and 21. To apply visit www.wru.wales/youthboard
The Foster's Challenge Cup will involve the 12 Principality Premiership sides and will run during European and British & Irish Cup weeks, providing vital fixtures for the participating clubs and an opportunity for upcoming players to step up to semi-professional rugby and make a claim for starting places within the Premiership squads.
Eighty schools and colleges in Wales now have a full time rugby officer as part of the WRU's school club hub scheme. All of the school club hub officers recently gathered at the National Centre of Excellence for various workshops.
With Liam Williams forced out of the World Cup through injury, lock Luke Charteris and Skills Coach Neil Jenkins say they have to put yesterday's defeat behind them as Wales now look ahead to another physical encounter against South Africa in the quarter-finals of the Rugby World Cup.
WRU Consultant Head of Physical Performance Paul Stridgeon praises the Physical Performance department for their work and dedication as he addresses the media ahead of Wales' Pool A clash against Australia
Twelve young people have been selected to follow a one year WRU Coach Core apprenticeship programme. Coach Core was set up by the Royal Foundation of the Duke and Duchess of Cambridge and Prince Harry as part of the Olympics legacy in 2012 and the Duke of Cambridge was on hand to meet the apprentices on their first day in the job. The programme has been funded by the Hunter Foundation.
The WRU has launched a campaign to create a long term legacy for Welsh club rugby by highlighting the advantages of volunteering. Rhian Edwards, a volunteer at Seven Sisters, has enjoyed many benefits of her volunteering at a grassroots rugby club including being part of the Rugby World Cup volunteer workforce after being nominated by the WRU - and the WRU is asking for more people to develop their 'Welsh rugby roots'.