Gavin Evans pounced for a opportunist try as Cardiff Blues held on for a hard-fought victory over London Irish.
The Blues were already out of the LV=Cup but they produced a committed performance as Phil Davies' men followed the lead of Wales Under-20s with a victory over Irish opposition.
Tom Homer kicked the visitors in front but he failed to control Rhys Patchell's kick as Evans capitalised.
The Blues made a bright start in the difficult conditions at the Arms Park, with both Patchell and Michael Paterson threatening on the counter attack but it was the Exiles that took the lead thanks to the boot of Homer.
Cardiff fought back and they surged into the lead as Homer appeared to flap at Patchell's long kick to allow Evans to snatch an opportunist score.
Patchell slotted the extras to hand the Blues a 7-3 lead at the break.
The Exiles came flying out of the blocks in the second-half and Guy Armitage almost burst clear for an early try but the Blues scramble defence was up to the task.
Homer cut the deficit to a single-point after Cardiff were penalised at the scrum on 54 minutes.
But again the Blues rallied with Patchell and captain, Evans and Jason Tovey at the fore. They twice came close to crossing the whitewash but Irish held on.
Patchell missed a second shot at goal on 60 minutes but he quickly made amends to restore the slender advantage.
The English club dominated exchanges at the death but Phil Davies' men defended heroically to secure the win.
Team coach Brett Davey is aiming to keep his unbeaten run in cup finals at Principality Stadium intact when his side take on Amman United in the WRU Bowl final, after he guided Caerphilly to a 20-14 win against Cilfynydd in the semi-finals.
Penallta are hoping to go one step further than last season when falling to Bedlinog in the WRU Plate Final. After a titanic struggle against Nant Conwy, they have given themselves a great chance, after a hard fought 18-13 semi-final victory.
The unique jeopardy of Judgement Day V has been described by stars from Cardiff Blues, Ospreys, Scarlets and Newport Gwent Dragons who will face each other in the annual double-header at Principality Stadium on 15th April.
School club hub officers in schools throughout Wales are enriching lives by helping pupils to engage more with their education, their community and improve their own outlook on life and future prospects by improving confidence and developing skills such as leadership.
WRU chief executive Martyn Phillips, WRU chairman Gareth Davies and Dragons chief executive Stuart Davies discuss the historic intentions of the governing body to assume operational control of the Newport Gwent Dragons, with a targeted completion date of 1st July.
Equal access to facilities and resources at St Helen's has seen Swansea Women flourish since being welcomed with open arms last July. Swansea RFC chairman Stephen Hughes and women's captain Siwan Lillicrap are delighted to see rapid progress being made on and off the pitch.
Young referee Ben Breakspear is making rapid strides as a referee. In just over a year he has gone from officiating a college game to being a touchline official during last weekend's RBS 6 Nations clash between Wales and Ireland at Principality Stadium.
Grand Slams, Triple Crowns and British and Irish Lions tours - Sir Gareth Edwards did it all. But what are his favourite moments in what was an amazing career? WRU TV finds out - along with his favourite players of today in the third and final instalment of our series with the greatest rugby player ever.
JPR Williams, Gerald Davies and Mervyn Davies were among those in the Welsh ranks when Sir Gareth Edwards began his international career against France nearly 50 years ago, but who was the player who took the young scrum half under their wing?
Wales head coach Rob Howley and captain Alun Wyn Jones are expecting a physical battle against France on Saturday but both are hoping for another impact from the bench as the men in red chase a top-four world ranking.
It's nearly 50 years since the great Sir Gareth Edwards made his debut as a youngster for Wales against France in Stade Colombes. In the first of a series, WRU TV discovers he pocketed a 'special momento' from the game - something he still has today.