A strong defensive display earned Munster an opening Guinness Pro12 victory over a disappointing Scarlets at Parc y Scarlets.

Scarlets had much more of the possession and territory but Munster emerged winners by two tries to one.

The Irish side's tries came from prop James Cronin and wing Ronan O'Mahony with outside-half Tyler Bleyendaal kicking 10 points and Ian Keatley adding a penalty in the 23-13 victory. Scrum-half Gareth Davies claimed Scarlets' only try with outside-half Rhys Patchell kicking eight points.

Patchell, South African prop Werner Kruger and 19-year-old number eight Josh Macleod all made their debut for Scarlets with Wales centre Jonathan Davies coming off the bench in the second half after rejoining the region from Clermont Auvergne. In all Scarlets named 11 internationals in their 23-man squad.

Centre Dan Goggin made his first start for Munster, who also included full-back Simon Zebo and flanker Tommy O'Donnell.

Despite a wealth of possession for Scarlets and a lot of mistakes from Munster at line-outs and restarts, it was the Irish side who went in at half-time with a 17-10 lead.

Scarlets spent most of the first quarter in Munster's half but could not get on the scoreboard with Patchell missing an 11th minute penalty goal attempt.

Munster suffered a setback when Zebo was forced off with a rib injury but with their first visit into Scarlets' 22 they scored with Cronin getting the ball down under the posts for Bleyendaal to add the conversion.

Scarlets got some points on the board with a Patchell penalty on 27 minutes but three minutes later O'Mahony ran through a huge gap to claim Munster's second try. Bleyendaal's conversion made it 14-3 on the half-hour mark.

Scarlets needed something special to get back in the game and they got it with a quick tap penalty deep in his own half from Davies, who broke free kicked ahead and reclaimed the ball to score the try, which was converted by Patchell.

But Munster had the final say of the half when Bleyendaal kicked a penalty two minutes before the break.

The South African missed a relatively easy penalty attempt at the start of the second half, while Patchell found the target with his own penalty shot on 48 minutes to reduce the deficit to four points.

But Scarlets continued to have no answer to Munster's strong defensive effort and on 54 minutes Bleyendaal restored his side's seven-point lead with his second penalty kick.

And any chance Scarlets had of getting back in the game seemed to go when a Scarlets penalty was reversed after lock Lewis Rawlins dropped the shoulder at a ruck. Keatley stepped up to kick the long range penalty to extent Munster's lead to 10 points.

In the final minute Patchell missed a penalty which if he had converted it would have earned Scarlets a bonus point. It was Scarlets' third successive home defeat after they lost their final two matches at Parc y Scarlets last season.