The South, who needed just a losing bonus point from the game to book their place in the final against Blues North, pressed until late on in the game at Llandovery, but eventually went down 10-0.
The date of the final has yet to be confirmed but Kevin George, WRU regional performance development manager for the Scarlets said; “It was a tough game and went right to the wire.The boys battled to the end and got what they deserved.
“It is something for everyone to look forward to at the end of a very hard but rewarding season so far.”