The Blues, who swept through their pre season unbeaten, have kicked off the competitive campaign with outstanding victories over the Scarlets (18-6) and Gogledd Cymru (58-0).
And in similar fashion and with equal excellence, the Ospreys have also been in unbeatable form - an opening 37-12 victory over Gogledd Cymru in Colwyn Bay was preceded a 28-16 win at Newbridge against a very good Dragons' side.
Eli Walker and Bowdy Davies have been leading the way for tomorrow's hosts, whilst for the Blues, it has been Joseff Griffin who has two stolen the show in terms of points scored.
Griffin bagged a try and eight points with the boot in the victory at Parc y Scarlets and added four conversions in the bonus point victory over North Wales.
That game brought nine tries in total, including a hat-trick from Sam Campbell who once again partners Ciaran Driscoll in midfield.
On Sunday, the Dragons are in N orth Wales to take on Gogledd Cymru.
Blues: H Thomson; E Jones, C Driscoll, S Campbell, H Robinson; J Griffin, L Jones, D Harris, J Dando, B Thyer, M Screech, C Hill, C Thomas, T Young (capt), T Tucker. Replacements: J Elley, W Griff-John, T Davies, A Lee, E Jenkins, A Meades, T Pascoe
Blues U18 team to play Ospreys U18 at Llandarcy - 7.15pm tomorrow (Wednesday) -
15. Harley Thompson 14. Elliot Jones 13. Ciaran Driscoll 12. Sam Campbell 11. Harry Robinson, 10. Joseff Griffin 9. Lewis Jones
1. Darren Harris 2. Jack Done 3. Bradley Thompson 4. Matthew Screech 5. Cory Hill 6. Calum Thomas 7. Thomas Young © 8. Reuben Tucker
16. Jon Elley 17. Will Griff John 18. Thomas Davies 19. Alwyn Lee 20. Ellis Jenkins 21. Adam Meades 22. Thomas Pascoe