In the latest round of the Under 16s WRU Championship both Blues North and Blues South were in action.
There were mixed fortunes for the Blues under 16s with the South beating the Scarlets at Stradey Park and the North going down to the new leaders, the Ospreys.
The Ospreys, made the short trip to Abercynon to play a rejuvenated North side and romped home 30-5 thanks to a hat trick of tries from outstanding centre Christian Phillips, a fourth from fellow centre Ashley Beck and a fifth from full back Scott Hancock.
Daniel Lewis scored the Blues' only points courtesy of a first half try.
In the west, however, there was much better news for the region with the South defeating the struggling Scarlets 21-15. Outside half Joe Deacon kicked six points with flanker Cory Hearn, scrum half Tom Marley and centre Rhys Meredith completing a fine night's work with tries.
A penalty try and a try from scrum half Tom James kept the Scarlets in touch but the Blues held on for a crucial away win.
The victory keeps the South in third place but the Ospreys leapfrog the Dragons to assume top spot despite having played a game more.