Scarlets moved in to sixth spot on the Pro12 table after claiming a 16-6 victory over Cardiff Blues at Parc y Scarlets on Sunday.
The win puts Scarlets in pole position to qualify for next season's European Champions Cup.
Rhys Priestland kicked three penalties to Rhys Patchell's one to take the home side 9-3 in front at the interval.
Patchell scored his second three-pointer in the final period, but the Blues couldn't build on that and Ken Owens' try secured a crucial result for the hosts.
Although Wayne Pivac's men were looking to move into a guaranteed Champions Cup qualification place, they started their game against Cardiff slowly.
It was the visitors who created problems for the Llanelli-based outfit's rearguard and, from a penetrative attack, Liam Williams cynically infringed and was duly yellow carded.
Patchell kicked the resultant penalty opportunity, but they failed to truly capitalise on the man advantage. Instead, it seemed to revitalise the hosts, who had initially struggled to impose themselves, and they levelled matters through Priestland despite being a player down.
The Scarlets then went ahead through their fly-half before the Wales' international scored his third from the tee to give them a 9-3 lead at the break.
Cardiff opened the second period with much more intent and Patchell reduced the arrears through a second three-pointer.
They also created further half-chances but their failure to make full use of them proved costly as Owens drove over for the top-six contenders.
Despite being 10 points down, the Blues struggled to lift the intensity and it was the hosts who ended the match on the front foot, although they failed to add to the score.
Pens: Priestland 3
Yellow card: L Williams
For Cardiff Blues:
Pens: Patchell 2
Scarlets: 15 Liam Williams, 14 Harry Robinson, 13 Hadleigh Parkes, 12 Scott Williams, 11 Steff Evans, 10 Rhys Priestland, 9 Aled Davies, 8 John Barclay, 7 James Davies, 6 Aaron Shingler, 5 Lewis Rawlins, 4 Jake Ball, 3 Peter Edwards, 2 Ken Owens (c), 1 Phil John
Replacements: 16 Ryan Elias, 17 Rob Evans, 18 Jacobie Adriaanse, 19 George Earle, 20 Rory Pitman, 21 Rhodri Williams, 22 Steven Shingler, 23 Adam Warren
Cardiff Blues: 15 Gareth Anscombe, 14 Alex Cuthbert, 13 Garyn Smith, 12 Gavin Evans, 11 Joaquin Tuculet, 10 Rhys Patchell, 9 Lloyd Williams, 8 Josh Navidi, 7 Sam Warburton, 6 Josh Turnbull, 5 Filo Paulo, 4 Jarrad Hoeata, 3 Craig Mitchell, 2 Matthew Rees (c), 1 Thomas Davies
Replacements: 16 Rhys Williams, 17 Sam Hobbs, 18 Scott Andrews, 19 Lou Reed, 20 Manoa Vosawai, 21Tavis Knoyle, 22 Tom Isaacs, 23 Richard Smith
Referee: John Lacey (Ireland)