Celtic League: The final scoreline flattered Llanelli but Leinster won't care after their young team produced an excellent performance, albeit marred by a serious leg injury to prop Niall Treston, to claim a fourth successive victory.

It was a superb team performance, embellished by a towering display from the back row, hooker Gavin Hickie and Gordon D'Arcy behind the scrum.

Leinster coach Gary Ella will have been pleased with the organisation in defence as much as anything that his team achieved with the ball.

There was a 15-minute period in which Llanelli dominated territorially and in terms of possession but they encountered measured resistance, whether 30 metres out or three.

Indeed, Leinster's discipline was equally commendable as was their ability to turn over possession and in that respect, the young back row of Niall Breslin, Shane Jennings and Des Dillon were outstanding. It is the intelligence as well as the athleticism that marks them as players of burgeoning talent.

Hooker Gavin Hickie was another to thrive, conspicuous in the loose and flawless out of touch. In essence, the whole pack contributed, providing a decent platform in that period.

Behind the scrum it was the dancing feet of Gordon D'Arcy and Gary Browne that invariably beat the first tackle and created gaps in the visiting defence.

Brian O'Meara and Llanelli outhalf Gareth Bowen exchanged early penalties before the visitors enjoyed a sustained period of pressure in the Leinster 22. The home side survived, by inches on a couple of occasions.

Leinster had earlier given notice that they could counter-attack from deep and it was from just such a scenario that they look the lead on 21 minutes.

Browne left a couple of Llanelli defenders grasping air on a slaloming run, and D'Arcy, Niall Treston and Jennings were just a few of the players who enabled Christian Warner to cut clear on the Llanelli 22, showing good speed to take it under the posts.

O'Meara converted and tagged on a couple of penalties before the interval.

It was the least Leinster deserved and, but for impatience in the Llanelli 22, they might have added to their try tally.

Their 16-6 interval lead looked a little precarious when Leinster lost second row Ben Gissing to the sin bin four minutes after the restart, but five minutes later referee Rob Dickson brandished yellow for Llanelli second row James Griffiths, deliberate offside the offence.

It had followed a wonderful break from D'Arcy that deserved more than the knock-on that ended the move from the following ruck. When Leinster were winning quick ruck ball, they were producing marvellous rugby: quick hands, clever angles and superb support play.

Bowen and O'Meara swapped penalties before the home side cut loose with two superb tries, both finished with aplomb by right wing John McWeeney. The first was the product of excellent team play, switching the point of attack several times, before McWeeney burst through a gap on a 15-metre surge.

His next try came once again from a counter-attack, O'Meara kicked intelligently, Warner won the footrace, Kearney conjured a magnificent one-handed pick-up, and from the ruck, McWeeney trailed Quinlan for the inside pass.

What had been an excellent evening for the home side soured on 65 minutes when Treston, who had enjoyed a fine match, suffered a serious leg injury that necessitated a stretcher and a 10-minute delay.

Llanelli responded with a try from Tal Selley, converted by Barry Davies, to reduce the deficit to 31-13 and despite referee Dickson farcically playing 17 minutes of injury time - at the end of which Ian Boobyer added a try for the visitors - Leinster were full value for a fine victory.

SCORING SEQUENCE: 2 mins: O'Meara penalty, 3-0; 4: Bowen penalty, 3-3; 26: Warner try, O'Meara conversion, 10-3; 29: O'Meara penalty, 13-3; 40 (+3): O'Meara penalty, 16-3. Half-time: 16-3. 44: Bowen penalty, 16-6; 48: O'Meara penalty, 19-6; 56: McWeeney try, O'Meara conversion, 26-6; 58: McWeeney try, 31-6; 72: Selley try, B Davies conversion, 31-13; 97: Boobyer try, Davies conversion, 31-20.

LEINSTER: G D'Arcy; J McWeeney, C Warner, D Quinlan, G Brown; M Leek, B O'Meara; E Byrne, G Hickie, N Treston, B Gissing, A Kearney, N Breslin, D Dillon, S Jennings (capt). Replacements: P McKenna for D'Arcy 30-33 mins; P Coyle for Treston 65 mins; D Blaney for Hickie 74 mins; C Potts for Breslin 79 mins; N Ronan for Jennings 81 mins; S Whelan for O'Meara 89 mins.

LLANELLI: B Davies; R Rees, T Selley, M Watkins, S Finau; G Bowen, M Phillips; P John, A Gravelle, J Davies, J Griffiths, A Jones, V Cooper, E Lewis, I Boobyer. Replacements: L Byrne for Watkins 65 mins; R Williams for Gravelle 65 mins; C Thomas for Bowen 74 mins.

Referee: R Dickson (Scotland).

Yellow cards: B Gissing (Leinster) 44-54 mins; J Griffiths (Llanelli) 48-58 mins.