The Scarlets saw off regional Welsh rivals Cardiff Blues 27-15 at Parc y Scarlets to conclude their PRO12 season on Saturday.
Scarlets were looking to build on last week's win over Newport Gwent Dragons, while the Blues were seeking a fifth win in as many games.
Scarlets took the lead in the 13th minute, when Jake Ball's pass created the opportunity for Rhodri Williams to cross for an eye-catching try. Rhys Priestland added the extras, but just five minutes later the Blues struck back through Macauley Cook's score in the corner.
The conversion was missed, but the visitors took the lead later in the first half through Simon Humberstone's penalty, and the lead stood until the final stages of the first period, when Priestland responded in kind to make it 10-8 at the break.
Early in the second half Scarlets extended their lead, when Williams produced a moment of individual magic to crash over. Priestland converted to put Scarlets nine points in front, but despite continued home pressure, the Blues remained in contention through a penalty try, awarded after the hosts were pinged for pulling down a maul.
Humberstone added the conversion to make it 17-15 with plenty of time left on the clock, but the hosts found an extra gear in the final stages to take the game away from the Blues. Stephen Shingler booted over a penalty to make it 20-15, and he converted his own try shortly after to nail down a 12-point victory for Scarlets.
Tries: R. Williams, L. Williams, S. Shingler
Cons: Priestland, S. Shingler 2
Pens: Priestland, S. Shingler
Tries: Cook, Penalty Try
Cons: Humberstone 2
Scarlets:15 Liam Williams, 14 Kristian Phillips, 13 Jonathan Davies (c), 12 Steven Shingler, 11 Jordan Williams, 10 Rhys Priestland, 9 Rhodri Williams, 8 Rob McCusker 7 Aaron Shingler, 6 Josh Turnbull, 5 Johan Snyman, 4 Jake Ball, 3 Samson Lee, 2 Ken Owens, 1 Phil John,
Replacements: 16 Kirby Myhill, 17 Rob Evans, 18 Rhodri Jones, 19 Richard Kelly, 20 Sione Timani, 21 Gareth Davies, 22 Olly Barkley, 23 Gareth Maule
Cardiff Blues : 15 Dan Fish, 14 Alex Cuthbert, 13 Cory Allen, 12 Isaia Tuifua, 11 Harry Robinson, 10 Simon Humberstone, 9 Lewis Jones, 8 Robin Copeland, 7 Josh Navidi, 6 Macauley Cook, 5 Filo Paulo, 4 Bradley Davies, 3 Taufa'ao Filise, 2 Matthew Rees (c), 1 Gethin Jenkins.
Replacements: 16 Kristian Dacey, 17 Thomas Davies, 18 Scott Andrews, 19 Chris Dicomidis, 20 Ellis Jenkins, 21 Lloyd Williams, 22 Dafydd Hewitt, 23 Thomas Williams
Referee: Ian Davies (WRU)