Blues North under 16s need to win just one of their remaining games in the WRU Reebok Regional Championship to book a place in next month's final at Sardis Road.
However, those games are against the Ospreys and Scarlets who, after last night's rearranged matches, are locked together in second place, just a single point behind the North.
Unfortunately, for Blues South, a 19-0 home defeat to the Scarlets put paid to their slim hopes of reaching the final for only the second time since the inception of the competition four years ago.
Having played so well this season, it should have come as no great surprise that the North bagged a four-try bonus point in their resounding 27-12 victory over the Dragons at Machen.
Alex Webber scored the only try of the first half to edge the North infront, but second half scores from Owain Sheppeard, Karl Williams and Tom Young made sure of the spoils and a bonus to boot.
Jospeh Griffin weighed in with a brace of conversions and a penalty whilst for the Dragons, who failed to score before half time, there were tries for Lewis Roblin and Rhyddian Wilson. Roblin converted his own try on the hour, but it was not enough to deny the North a valuable win.
At Penarth, there was precious little first half scoring too, with the Scarlets leading just 7-0 at the interval thanks to a try from flanker Sam Parry.
Luke Williams, Jamie Kaijacks scored in the second half with full back James Russell landing two conversions.