Pontypridd clinched their third SWALEC Cup in four seasons with a 21-8 victory over Cross Keys at the Millennium Stadium.
Paul John's men kept their hopes alive of an historic double, which would see them become the first side to win the league and cup two seasons in a row.
Ponty avenged their 2012 final defeat at the hands of Keys with tries from James Howe and Gavin Dacey and 11 points from the boot of Simon Humberstone.
Nathan Trowbridge scored a try to lift his team's hopes of victory, but the Keys couldn't force their way past strong Pontypridd defence.
Fly-half Dorian Jones thumped Cross Keys into the lead after 10 minutes. But his counterpart Humberstone, who played in the Blues victory over Connacht less than 24 hours before, slotted a penalty two minutes later to level the scores.
An electric break from Ponty wing Lewis Williams almost gave his side the lead before the Principality Premiership leaders rumbled over for their first try.
Locke collected Aled Morris's line-out throw and the Pontypridd pack shunted Howe over the line to score and boost his team's hopes of a second double in as many seasons.
Jones had the chance to pull Ponty's lead back to two points after the men from Sardis Road were caught offside. But the Keys kicker saw his long-range shot drop just short.
Keys scrum-half Rhys Dyer was then penalised for obstruction as Elliot Jones sliced through the defensive line.
And Humberstone stretched the Valley Commandos' lead to eight points three minutes from half-time with a 45-metre penalty.
The Ponty stand-off kept the scoreboard ticking over with a well-timed drop goal to give his side a 14-3 advantage just after half-time.
The decisive score came through centre Dacey after 62 minutes.Man-of-the-match Geraint Walsh found talismanic captain Dafydd Lockyer running a dangerous angle, he sliced through and picked out Dacey who crashed over from five metres out.
Cross Keys hit-back just three minutes later to prove they were far from finished. Replacement scrum-half Trowbridge sniped through a gap in the defence to score - but Steffan Jones missed the conversion.
Wales reached their first semi-final since 2013 in the opening round of this season's HSBC World Rugby Sevens Series in Dubai. WRU TV's Graeme Gillespie recaps on what proved to be an eventful tournament
Wales and Ospreys back row James King, who came through the North Wales age grade system, nominated North Wales Regional Community Rugby Manager Marc Roberts, in the WRU's 'Diolch' initiative where squad players thanked those who played a part in their rise to the top.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series