Blues (10) 10 Try: Sweeney Con: Sweeney Pen: Sweeney Scarlets (9) 16 Tries: Priestland Con: S Jones Pens: Priestland 3
Rhys Priestland beats Ceri Sweeney as the Scarlets win at Cardiff City Stadium
The Scarlets ended Cardiff Blues' six-match unbeaten home run in a gritty, stop-start Welsh Magners League derby at Cardiff City Stadium.
The Blues earned a bonus point, but saw the visitors rise above them into second place in the league.
Ceri Sweeney scored all the hosts points in the first-half with a penalty, try and conversion.
But in-form Priestland kicked three first-half penalties and his second-half try won it for the Scarlets.
Jonathan Davies was a late withdrawal from the Scarlets team due to 'fitness issues' and was replaced by Regan King.
The Scarlets were also without David Lyons (shoulder) and Rhys Thomas (broken leg).
Wales squad prop Scott Andrews was handed only his eighth Blues start with Chris Czekaj named at full-back.
The Scarlets had the better of play in the opening period, but trailed 10-9 at the break having been unable to convert their pressure into points.
Nigel Davies' side were twice denied by players failing to ground the ball as they crossed the line.
Richie Rees creates Ceri Sweeney's first-half Blues try
Video referee Gareth Simmonds deemed prop Iestyn Thomas to have failed in his attempt as he crossed on his back.
And late call-up Ben Morgan dropped the ball as he went over in the last play of the game.
Scarlets fly-half Priestland kicked the game's first points after 10 minutes, having watched opposite number Sweeney miss his first shot at goal. But Sweeney drew level five minutes later.
Visiting wing Morgan Stoddart was penalised for a dangerous tackle on Halfpenny and with the visitors having committed 12 offences in the first 20 minutes then found himself in the sin-bin for offside.
In his absence the Blues enjoyed their most telling period of first-half pressure and with Richie Rees sparking their attacks, the reward soon came.
Casey Laulala was at the heart of the move that took the Blues to within striking distance and as the Scarlets defence was stretched, Wales squad member Rees drew two defenders with a threatening run to send Sweeney over.
The fly-half converted only for Priestland to reply with a penalty and the Blues to soon find themselves also down to 14 men after South African flanker Andries Pretorius went off his feet at a ruck.
Priestland missed another shot at goal, but made amends two minutes from the break and then saw video ref Simmonds rule out Morgan's effort.
In the meantime Blues scrum-half Rees was sin-binned for deliberately knocking on as Daniel Evans threatened to send Tavis Knoyle on his way to the line.
The Scarlets continued to threaten after the break and had the good fortune to be able to being on Wales fly-half Stephen Jones when Stoddart limped off.
Jones assumed the stand-off duties and promptly created a try for Priestland. Jones' cross kick flummoxed home defenders Gavin Evans and Chris Czekaj and Sean Lamont tapped back to Priestland who raced 40 metres to touch down.
Jones converted, but Priestland failed with a respectable long-range penalty effort to leave them 16-10 ahead.
It stayed that way despite the Scarlets finishing with 14 men after replacement Dominic Day was sin-binned for offside amid the Blues' late attempts to reclaim the lead.
Cardiff Blues: Czekaj; Halfpenny, Laulala, Hewitt, James; Sweeney, Rees; G Jenkins, R Thomas, Andrews, B Davies, Paterson, Pretorius, Warburton, Rush. Replacements: Evans for Halfpenny (40), Mustoe for James (21), L. Williams for Rees (70), R. Williams for Thomas (61), Filise for Andrews (52), Tito for Paterson (52), Molitika for Pretorius (55). Not Used: Yapp.
Yellow cards: Pretorius (29), Rees (39).
Scarlets: Evans; Stoddart, Maule, King, Lamont (capt), Priestland; Knoyle, I Thomas, Owens, Manu, Reed, Welch, McCusker, Turnbull, Morgan. Replacements: S Jones for Evans (58), S Williams for Stoddart (58), P Edwards for I Thomas (77), Rees for Owens (53), Day for Welch (75), Pugh for McCusker (68). Not Used: Roberts, R Jones.
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