The Ospreys will take on Blues North in the final of the WRU Reebok Regional under 16 Championship final next Wednesday (5 March, 7.15pm, Sardis Road) after putting one over on the table topping Blues this week.
Needing a victory of any sort to pip the Scarlets to a place in next week's final at Sardis Road, the Ospreys ran out 29-15 winners, thanks to four tries.
The North, who had already booked their place in the final, scored tries through flanker Openside Thomas Young, wing Owain Williams and flanker Jack Gibbon crossed for tries for the Blues, whilst for the Ospreys there were four tries - from wing Bowdy Davies (2), Ben Davies and replacement Kyle Blackmore.
Tom Prydie with two conversions and Davies with one, wound up proceedings with team manager Graham Court saying; "we are delighted to have made it through to the final, now we have to repeat this performance.
"If the game is half as good as this one, it will be worth watching."
Blues high performance manager Gafyn Cooper said, "It is great for this side to have achieved what they have this seasopn, but they need to finish off the campaign with one final victory."
Judgement Day is back at the Millennium Stadium for 2015 with the Welsh Rugby Union (WRU) and Regions confirming today that tickets will cost just £10 per head to see all four of Wales' GUINNESS PRO12 sides in action under one roof.
Battling Cardiff Blues produce a performance of full pride and heart in adversity as they lost out to reigning champions Leinster Rugby in a pulsating Guinness PRO12 encounter at BT Sport Cardiff Arms Park.
Cory Allen scored the only try of the game as Cardiff Blues edged an absorbing and dramatic Welsh derby with Newport Gwent Dragons at Rodney Parade to open 2015 in the Guinness PRO12 with a crucial victory.