Four penalties from outside half Jordan Williams put the Scarlets Under 16s to within a whisker of a place in the WRU Age Grade Championship final.
However, it was another disappointment for Blues North who were combative at forward but unable to press home that advantage behind the scrum as they went down 12-0 at Aberdare.
Williams, who is the leading scorer in this season’s competition, kicked his side into a 9-0 lead at the interval before making sure of a sixth straight victory of the campaign with his fourth in the second half.
On the back of his match-winning performance for the region’s under 18s last week, it was further confirmation that the outstanding youngster is certainly one to watch.
Blues North team manager Nigel Way said; “We are pleased with areas of our development and that, for these boys, is the most important aspect.
“However, having done so well as a squad over the past couple of years, it is disappointing that we have not enjoyed one or two better results.”
The game between the Dragons and Blues South, scheduled for Tredegar, was postponed due to a waterlogged pitch.