Currently five points clear of second placed Blues, the Scarlets will take themselves 13 points clear of the other three regional sides if they complete the double over the Gwent region with a bonus point victory. That would be enough to book their spot in the final.
Two tries from George North and a third from Kirby Myhill was enough to see off the Dragons at Newbridge back in September with the visitors eventually running out 19-13.
Meanwhile, the Under 16 Championship is a great deal closer with all six sides still in with a chance of qualifying for the final.
Scarlets Under 18s: L Treharne; G Hunter, L Williams, R James, I Evans; J Williams, R Williams; R Evans, K Myhill, S Lee, G Thomas, C Morris, L Morris, T Powell, D Colman.
Replacements: N Bowen, O Lloyd, J Frater, S Maynard, A Powell, J Russell, T Ellis-Williams
Dragons: S Bevan; A Cooper, B Hill, L Bellamore, T Ashmead; J Prosser, J Evans (capt); L Bacon, J Williams, G Kemp, H Lewis, C Regan, J Sollis, K Tayler, M Thomas.
Replacements: C Owen, J-B Bruzilier, S Jones, D Haile, J Lavender, I Jones, R Stephens