Ben Blair kicked off and the Blues attacked relentlessly until they won a penalty after only two minutes. However Blair hit the upright and the Scarlets cleared; but the Blues attacked again.
However, it was the Scarlets who got the first points of the night with a Daniel Evans penalty. Blair soon equalised.
The Blues looked to attack wherever possible with Sam Norton Knight looking comfortable controlling things at outside half.
Jamie Roberts and Tom Shanklin were punching holes in the Scarlets defence but it was a neat slip pass from Rush that nearly created the score when Blair came to within inches of scoring in the left corner before the Scarlets eventually cleared again.
The match was a great spectacle with both Blues and Scarlets attacking, Sean Lamont beating Shanklin on the outside before a strong looking Mustoe pulled him down.
A great take by Paul Tito on a Scarlets line out and drive by the forwards saw the Blues launch an attack. Rush took it on before Mustoe, who was having a great game on the wing, broke down the wing showing great strength and speed. The ball eventually came left where Rush flipped the ball inside for Tito to crash over. Blair converted and added a long range penalty just before half time to bring the score to 13-3.
The Scarlets had one last chance before the close of the first half but the Blues kept them out.
Half Time
Cardiff Blues 13 Scarlets 3
Daniel Evans missed a long range effort for the Scarlets early on but Blair was accurate with his kicking, to extend the Blues lead. The blues were heaping pressure on the Scarlets with Filise charging down a clearance kick and Gareth Thomas putting in a thundering tackle on Mark Jones to turn the ball over.
The Scarlets made a number of subsitutions early in the second half and the Blues had Andy Powell, Darren Morris and Gavin Evans on by the hour mark. Despite the changes the game still flowed.
Norton Knight won a penalty for the Blues with some good counter attacking play and Blair again extended the lead.
The Blues put themselves under pressure in defence with Norton Knight passing on to Blair who was caught by three players. The Scarlets attacked but a thundering tackle by Shanklin on Maule seemed to have kept them out. Mathew Rees came very close to scoring under the posts but having referred to the TMO, Andrew Small judged that the ball did not cross the line. However, the Scarlets were awarded a scrum and David Lyons had the power to crash over. Evans converted.
The Scarlets struck back instantly from the restart. A well worked move saw them spread the ball wide with Jonathan Davies collecting an inside pass to sprint in from 40 yards. Evans missed the conversion but there was only four points in it with only 5 minutes left.
The Scarlets kicked their penalty a yard of the Blues line and won the line out, but the Blues stood firm and turned them over, winning a penalty. It was a tense finish but the Blues held on to record their first win at the stadium.
Cardiff Blues
15 Ben Blair 14 Richard Mustoe 80 off 13 Tom Shanklin 12 Jamie Roberts (36off) 11 Gareth Thomas 10 Sam Norton-Knight 9 Richie Rees 69 off
8 Xavier Rush 66off 7 Robin Sowden-Taylor 6 Maama Molitika 40 off 5 Paul Tito (C) 4 Bradley Davies 3 Taufaao Filise 62off 2 T Rhys Thomas 1 John Yapp
16 Darren Morris 62on 17 Gareth Williams 18 Deiniol Jones 66on 19 Andy Powell 40 on 20 Gareth Cooper 69 on 21 Ceri Sweeney 80 on 22 Gavin Evans (36on)
Scarlets
15 Daniel Evans, 14 Sean Lamont, 13 Gareth Maule, 12 Jonathan Davies, 11 Mark Jones (c), 10 Rhys Priestland, 9 Martin Roberts,
1 Iestyn Thomas, 2 Ken Owens, 3 Deacon Manu, 4 Lou Reed, 5 Dominic Day, 6 Simon Easterby, 7 Richie Pugh, 8 David Lyons. Reps
16 Phil John, 17 Matthew Rees, 18 Vernon Cooper, 19 Josh Turnbull, 20 Tavis Knoyle, 21 Dan Newton, 22 Lee Williams.
Referee: Andrew Small
Cardiff Blues
Try Tito x 1
Penalty Blair x 4
Con Blair x 1
D/Goal
Scarlets
Try Lyons x 1
Penalty Daniel Evans x 1
Con Evans x1
D/Goal