With one round of under 20 group games remaining, the two places in the WRU Regional Championship final are still very much up for grabs.
Victory for the Blues over the Ospreys, 31-24 at Waterton Cross, and a straightforward 46-13 success for the Scarlets over the Dragons at Stradey Park, means all three regions are still in with a chance of reaching the final on Januray 12.
Gareth Jones, Matthew Larsen and Luke Ford all crossed for tries for the Blues whilst for the Ospreys Jason Howells, Rhys Webb and Alex Wilkins scored tries with Leigh Halfpenny adding three conversions and a penalty.
The Blues, for whom Christian Baller added four penalties and a conversion, led 14-10 at half time and although the Ospreys struck twice in the second half through Webb and Wilkins, they held on for a victory which puts them back on course.
In the other game, the Scarlets and Dragons did well just to survive the horrendous conditions with high winds and heavy rain making life particularly difficult.
The Dragons scored a try through Tom Edwards and there was a conversion and two penalties from Gavin Ashman.
However, the Scarlets were too strong and bagged a bonus point thanks to tries from Lloyd Phillips (2), Haydn Pugh, Justin James, Emyr Phillips, Nick Cudd and Richard Thomas.
Stuart Morris kicked four conversions and a penalty for good measure with high performance manager Darryl Hill admitting, "I hav got to take my hat off to both sides, the conditions were terrible from start to finish."
Ron Schottle, the Dragons HPM, said, "We had one or two good performances out there, notably Jimmy Norris, but it was not to be.
"Had we have scored first in the second half it might have been a different story. But once they pulled away there was no comning back."
In the final games of the group stage on January 3, the Dragons entertain the Blues and the Scarlets go to the Ospreys.