Cardiff give Scarlets the Blues
Cardiff drew first blood in the festive Welsh derby season as their first-half dominance provided the platform for a welcome 21-9 win over Scarlets.
Man of the match Josh Navidi continued his outstanding recent form at number eight with two tries inside the opening half hour as the hosts built a 21-6 lead.
While the Scarlets were much improved in the second half, they spurned a series of try-scoring opportunities and it was the Blues who came away with just their third Guinness Pro12 victory of the season.
All the visitors' points came from the boot of Wales fly-half Rhys Priestland, with his opposite number Gareth Anscombe also landing three shots at goal.
The Scarlets had been forced into a late double change with Wales lock Jake Ball and flanker Aaron Shingler both ruled out through illness, which saw George Earle and young Lewis Rawlins called up to the pack.
It was the home team that totally dominated the opening quarter and their superiority was rewarded as they built up a 13-0 lead.
Fly-half Anscombe opened the scoring via an upright after the Scarlets scrum was penalised and he doubled their lead when centre Regan King was deemed guilty of a high tackle.
The Blues were on top up front and applying sustained pressure and they went further ahead with the opening try of the night on 18 minutes.
After Anscombe sent a pinpoint touchfinder to the corner, a wayward lineout throw handed the hosts a five-metre scrum.
It was then over to Navidi who picked up from the turning scrum and showed huge strength and determination as he fought so hard to reach the line and get the ball down, shaking off three would-be tacklers.
The Scarlets had hardly had a sniff up to that point, but finally managed to get some possession and territory which enabled Priestland to land a couple of penalties.
It was a brief respite for them however as the Blues reasserted control with the excellent Navidi claiming his second try.
Once again, the number eight showed real resolve to get over the whitewash, peeling away from a rolling maul and driving low for the line amid the feet of a quartet of Scarlet defenders.
Anscombe was wide with the conversion attempt, but made no mistake with an angled penalty to give his team a well deserved 21-6 interval lead after an opening half where they had 65 per cent possession.
Tempers spilled over early after the resumption when opposing second rows Filo Paulo and Johan Snyman exchanged blows off the ball, earning both of them 10 minutes in the sin-bin.
The Scarlets made a better start to the second half, securing a third Priestland penalty and came tantalisingly close to their first try when Rawlins spilled the ball with the line beckoning.
Another opportunity slipped away for them when replacement scrum-half Rhodri Williams was unable to hold on to a pass after a fine looping run from Priestland, with a third chance going begging following a Scott Williams break due to lack of outside support.
The visitors could not even capitalise when Navidi was yellow carded late on for a tip tackle and they left Arms Park pointless.