Gogledd Cymru's victory at Llandovery last week, placed a spanner in the works of the Scarlets, who looked an odds on bet to reach the January 11 final after back to back victories over Blues North and the Ospreys. However, they can put their bid back on track if they secure a bonus point victory over the Dragons at Tredegar.
The Scarlets have delayed naming their starting line up until just before kick off, but the competition's leading scorer Gethin Hunter will be looking to add to his nine-try haul against a Dragons side who went down 23-12 at Narberth back in October.
Blues South, whose victory over Blues North last month keeps them in with a shout, entertain the Ospreys who were 14-8 winners when the sides met at Llandarcy back in September.
Tomorrow night, it's the turn of the under 18s with the Dragons entertaining the Scarlets at Tredegar.
Dragons v Scarlets (Rhymney, 7.15)
Blues South v Ospreys (Taffs Well, 7.15)
Dragons v Scarlets (Tredegar 7.15)