The Ospreys and Scarlets Under 16s bagged victories in the WRU Age Grade Championship last night to put the pressure on previous leaders Blues North.
With the North not playing until Sunday, against North Wales, both regions made hay despite failing to pick up a bonus point.
Two victories in their opening three games became three in four for the Scarlets as tries from Gethin Hunter, Richard Bloomfield and Gareth Rees helped them to a 23-12 success over the Dragons at Narberth.
Meanwhile at Llandarcy, the Ospreys defeated Blues South 14-8 to secure a second win of the season.
Rhodri Lloyd gave the Dragons a 5-0 lead inside two minutes with his first try of the season and though Jordan Williams cut the lead with a penalty, Thomas Ashmead, with a try, and Josh Prosser's conversions helped the visitors into a 12-3 lead.
It was a different story after the interval with Hunter crossing for his fourth try of the campaign, after 53 minutes, and Williams adding a conversion and penalty for good measure.
However, it was not until the final quarter that the Scarlets pulled away with Bloomfield and Rees on the mark with tries.
Meanwhile at Llandarcy, a try from Cory Allen and penalty from James Morris kept the South in touch, but the Ospreys made the most of three yellow cards for the South and made sure of the victory spoils courtesy of three penalties from outside half Tom Carpenter and a try from centre Andrew Claypole.
High performance manager Gruff Rees said; "There were elements of the performance that need work, notably our finishing, but there was plenty of honest endeavour and we will take the win."
The SWALEC semi-final draws threw up some mouth-watering clashes in the Cup, Plate and Bowl as the 12 teams aim for the Millennium Stadium Finals Day. All the semi-finals are to be played on the weekend of April 12.
Welsh whistler Rhys Thomas continues to scale the heights of the game as he prepares to be an official in this weekend's Hong Kong Sevens tournament, undoubtedly the showpiece event on the World Series calendar.
Wales International Ian Evans and Wales and Lions legend Scott Quinnell swapped rugby balls for paint pots at Tonna during the RBS 6 Nations. They surprised club players with a special clubhouse makeover to launch NatWest RugbyForce 2014 - a programme developed in partnership with the WRU to make rugby clubs stronger businesses by improving and renovating their facilities with the support of volunteers and the local community.
Fresh from claiming the Bowl honours in Tokyo last Sunday, the Wales Sevens squad have settled into their routine as they prepare for this weekend's Hong Kong tournament where Iolo Evans is aiming high, as WRU TV's Graeme Gillespie discovers.
The Welsh Rugby Union has recently teamed up with Prostate Cymru to help the charity launch its latest campaign to raise awareness of the disease. Members of the Wales squad helped produce a short video and promotional material for the campaign titled 'The Best Defence - is to know the FACTS'.
Defending champions Coleg Sir Gar reached their second consecutive Millennium Stadium final as they defeated Coleg Gwent in the WRU Wednesday Under 18 play-off. Watch highlights of their narrow 10-8 win here.
Wales Sevens head coach Gareth Williams has freshened up his squad for the next two rounds of the World Series in Japan and Hong Kong where Tom Williams, Owen Jenkins and Ross Jones make the trip along with returning Alex Webber and Craig Price.