Wings Lee Halfpenny, with two, and Jason Howells bagged the tries for the Ospreys who, against the odds, actually led as the game moved into overtime. However, the Blues had enough in store to rally late on and take the victory points.
Tom Cole added the extras for the Ospreys with two conversions but it was a night that belonged to the Blues, who now top all three age grade tables.
Up the road at Virginia Park, Caerphilly, the Dragons were beaten 35-5 by a Scarlets side still smarting from their opening night defeat at the hands of the Blues. There were five tries in all for the Scarlets who led 14-0 in as many minutes and 28-5 at the interval. High Performance Manager Darryl Hill said: "We got off to a great start and that was that. We were a long way ahead at the interval and things were a little more even in the second half. However, we have got to be pleased with winning away here."
Centre Richard Thomas and fullback Daniel Evans both helped themselves to a pair of tries whilst replacement scrum half Justin James added the fifth late on. Evans added five conversions to finish the night with 20 points. Not even yellow cards for Alex Jenkins and Matthew Evans could put a dampener on an outstanding performance from the Scarlets.
Next week, the U16 take centre stage with the Blues North seeking a third successive victory of the new season over the Ospreys at Merthyr RFC. Having failed to win a game in the first season of Reebok Regional rugby, the North have picked up and proved themselves to be the current leading light in the U16 competition.
Blues High Performance Manager, Gafyn Cooper, said: "It has taken some time, but the boys and the coaches have worked tirelessly over the past two and a bit seasons to reach this position. We are delighted with the way things and have gone and a third win would certainly go down well."
In the other game, the Dragons entertain Blues South at Cross Keys with both sides in search of a first win of the campaign.