Full back Hallam Amos scored the only try of the match for the Dragons.
Newport Gwent Dragons Under 18s fended off the challenge from the Scarlets at Rodney Parade to advance to the final of the Regional Competition final.
In a keenly contested encounter, the home side ran out 8-6 victors with full back Hallam Amos scoring the only try of the match mid way through the second half to edge his side in front after the Scarlets had banged over two penalties to nose ahead after Dragons fly half Ethan Davies responded with a first half penalty.
The Dragons will now take on Cardiff Blues in the Regional Competiton final on Wednesday 18 January, at St Helens (KO 7.30pm).
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.