|Cardiff Blues (10) 29|
|Tries: Allen, Fish, Dacey, Cuthbert Cons: Patchell 3 Pens: Patchell|
|Scarlets (20) 27|
|Tries: Owens, DTH van der Merwe, G Davies Cons: Thomas 3 Pens: Thomas 2|
Alex Cuthbert's late try secured Cardiff Blues' second Pro12 derby win of the festive period in an enthralling game against Scarlets.
Ken Owens and DTH van der Merwe's tries put Scarlets in control with Cory Allen responding for the Blues.
Dan Fish crossed for the home side before Kristian Dacey's try put them in front, with Scarlets down to 13 men.
Gareth Davies' try restored Scarlets' lead but Cuthbert's late score secured Blues' third successive Pro12 win.
Blues are ninth in the table following their bonus-point win at a packed Arms Park.
Scarlets, who had three players yellow carded during the game, remain top despite suffering their second successive defeat after losing to Ospreys on Boxing Day.
Wales scrum-half Gareth Davies returned to the Scarlets starting line-up but they were without the injured Jake Ball and John Barclay.
For the Blues, Wales centre Cory Allen was handed his first league appearance of the season.
Rhys Patchell, who will join Scarlets in the summer, opened the scoring with an early penalty for the home side but two mistakes gifted the visitors the lead.
Scarlets responded with the game's first try, hooker Owens crossing after Dacey overthrew with Aled Thomas converting.
The visitors capitalised on another Blues mistake when DTH van der Merwe intercepted Tom James' pass and ran 60 metres to score under the posts.
Thomas again added the extras but Blues hit back when Rey Lee-Lo fed centre partner Allen, who raced over to score in the corner.
Patchell converted but two Thomas penalties gave Scarlets a 10-point advantage, although they had Lewis Rawlins sent to the sin-bin for dragging down a driving maul.
Blues had more possession and territory during the opening 40 minutes but Scarlets made the most of their opportunities.
The home side closed the gap early in the second half when good work from Manoa Vosawai and James set up full-back Dan Fish, who scored.
Scarlets were reduced to 13 men when Steffan Evans and Emyr Phillips were yellow carded in quick succession.
During their absence, Blues took full advantage with Dacey driving over for a try which was converted by Patchell to give them the lead for the first time.
But Scarlets, still down to 13 men, responded and Davies forced his way past an attempted tackle from Sam Hobbs and over the line for the try which Thomas converted.
Scarlets came under intense pressure on their try line but wing Cuthbert finally broke their resistance, burrowing over the line.
Cuthbert's try brought his side level and gave the Blues a bonus point, leaving Patchell to seal the win from the conversion.
Cardiff Blues head coach Danny Wilson said:
"I thought we performed well, especially after a slow start and giving the Scarlets opportunities to score.
"I can't say enough about this team at the moment. They're fighting hard for wins, wins that I'm hoping that are really going to springboard us on.
"The way we played is the way we're trying to master and we're slowly getting there."
Scarlets head coach Wayne Pivac said:
"It was a hotly contested game of rugby and maybe in hindsight we could have done a few things differently towards the end of the game.
"I don't think we helped ourselves with a little bit of discipline, obviously playing with 13 men at one stage was very difficult. That was very disappointing.
"We're going to pull that game to bits because we felt there were some inconsistencies in some of the decisions. We need to have a look at that before going further."
Cardiff Blues: Dan Fish; Alex Cuthbert, Cory Allen, Rey Lee-Lo, Tom James; Rhys Patchell, Lloyd Williams; Gethin Jenkins (capt), Kristian Dacey, Taufa'ao Filise; Jarrad Hoeata, James Down; Josh Turnbull, Josh Navidi, Manoa Vosawai.
Replacements: Ethan Lewis, Sam Hobbs, Dillon Lewis, Lou Reed, Macauley Cook, Tavis Knoyle, Jarrod Evans, Garyn Smith.
Scarlets: Michael Collins; Steff Evans, Gareth Owen, Hadleigh Parkes, DTH van der Merwe; Aled Thomas, Gareth Davies; Rob Evans, Ken Owens (capt), Samson Lee; Tom Price, Lewis Rawlins; Aaron Shingler, Jack Condy, Morgan Allen.
Replacements: Kirby Myhill, Phil John, Rhodri Jones, Maselino Paulino, Emyr Phillips, Aled Davies, Steve Shingler, Regan King.
Referee: Ben Whitehouse (WRU)
Assistant referees: Ian Davies, Gwyn Morris (WRU)
Citing commissioner: Gwyn Bowden (WRU)
TMO: Derek Bevan (WRU)