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.
Wales Head Coach Rob Howley talks to WRU TV's Sebastian Barrett about the 36-man squad he has just named for the forthcoming Under Armour series, which includes two uncapped players, Ospreys duo Sam Davies and Rory Thornton.
Head coach Rowland Phillips is deligthed he can now call BT Sport Cardiff Arms Park home for his Wales Women's side, who launch their international season next month with games against Scotland and UK Armed Forces in the heart of the capital city.
Wales Sevens star Sam Cross has put his home town club of Brynmawr on the map after winning a silver medal at the Rio Olympics with Team GB. His club have now honoured him by naming their players bar after him, as WRU TV discovered at the official launch, recently.
One of the newest members of the Principality Premiership, Bargoed admit it's proving to be a steep learning curve at the highest level, but are determined to become a force to be reckoned with. WRU TV visited the club last weekend when they took on Llanelli.
Table-topping Aberavon travel to north Wales to tackle RGC 1404 as both teams defend unbeaten starts to the season in the Principality Premiership. WRU TV's Graeme Gillespie visited the Wizards to see how their preparations were going for the game of the weekend.
The Half a Game initiative is currently sweeping across Wales and proving a major success. The scheme aims to give every young player at least half a game every weekend. WRU TV recently visited a festival in Narberth where clubs have fully embraced the initiative.
Both Bargoed and Swansea were seeking their first win of the Principality Premiership season this afternoon. It proved a fruitful day for the hosts - not only did they win, but Bargoed claimed a try bonus point.
Cardiff managed to keep their unbeaten record at home intact, but only just as Bridgend made them work extremely hard before the Blue and Blacks secured a hard fought Principality Premiership win at the BT Sport Arms Park last night.
Former Wales back row Andy Powell gives a guided tour of The Wern, home of Merthyr RFC, who are determined to prove a lot of people wrong and make their mark in their first season in the Principality Premiership.