Rhys Priestland kicked 17 points and controlled the game to lead the Scarlets to a 22-14 victory over local rivals the Ospreys.
The Scarlets dominated possession and territory in the early stages in front of a packed house at the Parc y Scarlets and Rhys Priestland, back marshalling the side at fly-half, kicked the Llanelli outfit into a 6-0 lead after quarter of an hour.
Dan Biggar did eventually register three points for the visitors on the half hour mark but this only served to spark the home side into action again and moments later they scored the opening try of the game through prop Rhys Thomas, who barrelled over from a yard out.
Priestland added the conversion and another penalty late on to give the Scarlets a comfortable looking 16-3 lead at the interval.
The visitors looked a completely different team after the break though. Scott Johnson's team talk had an immediate impact as his troops held on to the ball better and Biggar reduced the deficit with two early penalties.
Once they were back within range, the Ospreys visibly grew in confidence and, after spending some time in the opposition twenty-two, they made the most of an overlap on the right hand side and full-back Barry Davies slid over in the corner to make it 16-14.
Just as the Swansea-based side looked to be in the ascendancy though, Priestland steadied the ship with two crucial penalties for the Scarlets, who weathered a few storms late on to come away with a well-deserved victory.
Pens: Priestland 5
Try: BJ Davies
Pens: Biggar 3
Scarlets: 15 Liam Williams, 14 George North, 13 Scott Williams, 12 Jon Davies, 11 Sean Lamont, 10 Rhys Priestland, 9 Gareth Davies, 8 Ben Morgan, 7 Rob McCusker, 6 Aaron Shingler, 5 Dominic Day, 4 Lou Reed, 3 Rhys Thomas, 2 Matthew Rees (c), 1 Rhodri Jones.
Replacements: 16 Ken Owens, 17 Phil John, 18 Deacon Manu, 19 Sione Timani, 20 Johnathan Edwards, 21 Rhodri Williams, 22 Stephen Jones, 23 Iongi Viliame.
Ospreys: 15 Barry Davies, 14 Tommy Bowe, 13 Andrew Bishop, 12 Ashley Beck, 11 Shane Williams, 10 Dan Biggar, 9 Kahn Fotuali'i, 8 Joe Bearman, 7 Justin Tipuric (c), 6 Tom Smith, 5 Jonathan Thomas, 4 Ryan Jones, 3 Adam Jones, 2 Richard Hibbard, 1 Paul James.
Replacements: 16 Mefin Davies, 17 Ryan Bevington, 18 Aaron Jarvis, 19 James King, 20 George Stowers, 21 Rhys Webb, 22 Matthew Morgan, 23 Hanno Dirksen.