Llanelli Scarlets 13 Leinster 20:The euphemism about winning ugly was never more applicable than at Parc y Scarlets as Leinster managed to squeeze past their hosts in a game that should be exorcised from the memory banks with all due haste.

This Heineken Cup clash was a low grade contest riddled with mistakes as both sides graciously tossed errors backwards and forwards amid a welter of indiscipline. Leinster outhalf Jonathan Sexton kicked four penalties and a drop goal while Isa Nacewa crossed for a try.

In distilling the essence of the Irish province’s victory it came down to the fact that although Sexton missed three penalties he didn’t kick as poorly as his Scarlets’ counterpart Rhys Priestland, who had one of those days he’d sooner forget; it was in keeping with the general fare.

Leinster will focus on the four points gained and a precious away victory but they’ll know that this was another game in which they failed to find a consistent rhythm. There were aspects of the display that were heartening – a brilliant scrum – and for the second match in succession some timely turnovers.

They did make line breaks but a lack of precision, and at times patience – passes were forced – cost them a couple of tries at least. The Scarlets’ coach Simon Easterby will be really disappointed by his own side’s performance that was even more sloppy and fitful.

There was an intermittent carelessness to Leinster’s first-half performance and it must have frustrated coach Joe Schmidt. Handling errors, silly penalties and some poor application undermined enterprising patterns. Continuity was limited to less than half a dozen phases before a handling error, an unnecessary penalty or a forced pass saw the visitors cough up possession.

Precision would have nudged Leinster a long way down the track to winning this game in the first 40 minutes. As it was they had to settle for a well executed try and two penalties from the boot of Sexton.

The Leinster outhalf played a seminal part in Nacewa’s try on 10 minutes, his beautifully weighted cross-kick saw Nacewa not only out-jump the six foot four inch George North but when grabbed in the air the Fijian managed to wriggle free enough to ground the ball.

Sexton couldn’t add the conversion but his two penalties gave the Irish province a lead they thoroughly deserved but one that could have been appreciably bigger. On three occasions a Leinster player knocked the ball on, less than half a dozen metres from the Scarlets’ line. A couple could probably be attributed to unsympathetic passes while another was down to snatching at the pass.

The Scarlets couldn’t muster any continuity of their own, their best opportunity of the half came when Scott Williams slid a ball through for North but Eoin Reddan covered brilliantly to force the Welsh international into a knock on. Priestland – his line kicking was exceptional – missed with one long-range penalty.

Gordon D’Arcy, who equalled Shane Horgan’s Leinster record of 87 Heineken Cup appearances, was excellent on his return from injury: he defended with conviction, snaffling one great turnover and also broke the gain-line too. Shane Jennings has been outstanding this season and those standards didn’t drop.

Jamie Heaslip was conspicuous in a hard working backrow, Kevin McLaughlin worked hard too, but as a unit they were responsible for a smattering of the penalties at the breakdown.

Leinster started the second half with a similar lack of discipline that had afflicted them time and again in the first. Priestland missed the first opportunity of two but on 48 minutes landed a decent effort from long range. In between his two kicks, Sexton posted a wonderful 45 metre drop goal from a loose clearance by Scarlets fullback Liam Williams.

The next few minutes were less satisfactory for the Leinster and Ireland outhalf as he missed a relatively straightforward penalty and then kicked the ball out on the full. From the ensuring lineout Scarlet’s centre Gareth Maule stood up Brian O’Driscoll and then accelerated outside him to score a superb try in the corner which Priestland converted from the touchline; the home side trailed by just four points, 14-10 in a contest in which they should have been much further adrift on the scoreboard.

Sexton kicked a penalty to ease Leinster out into a 17-10 lead but it was a precarious advantage based on the visitors’ indiscipline and an ever spiralling number of basic mistakes.

Priestland’s horrible day with the boot and further compounded by another missed opportunity to narrow the gap. Sexton posted a penalty and then missed his third of the day soon after; both courtesy of monster scrums from the visiting eight. It probably explains why Mike Ross won the match of the match award.

The final throes of this contest were littered with yet more mistakes – a yellow card for Ian Madigan – the final whistle a relief in more ways than one.

Leinster’s hopes of topping Pool Five received a setback when tournament favourites Clermont Auvergne ran in six tries in a bonus-point 46-12 victory over Exeter Chiefs at Sandy Park.

French international centre Wesley Fofana and Fijian left-wing Napolioni Nalaga scored two tries each as Clermont moved on to 10 points, two clear of Leinster.

The two sides meet in back-to-back fixtures in rounds three in four, with Leinster visiting Stade Marcel Michelin on December 9th before the two sides meet at the Aviva Stadium on December 15th.

SCORING SEQUENCE - 1 min:Sexton penalty, 0-3; 10:Nacewa try, 0-8; 20:Sexton penalty, 0-11. Half-time:0-11. 44:Sexton drop goal 0-14; 48:Priestland penalty, 3-14; 55:Maule try, Priestland conversion, 10-14; 59:Sexton penalty, 10-17; 76:Sexton penalty, 10-20; 78:Priestland penalty, 13-20.

SCARLETS:L Williams; G North, G Maule, S Williams, A Fenby; R Priestland, T Knoyle; P John, M Rees, S Lee, G Earle, J Snyman, A Shingler, J Turnbull, R McCusker (capt).

Replacements:T Vallejos for Earle half-time; G Davies for Knoyle 53 mins; K Owens for Rees 59 mins; D Manu for Lee 59 mins; J Edwards for Snyman 65 mins; M Stoddart for Fenby 70 mins.

LEINSTER:I Madigan; F McFadden, B O'Driscoll, G D'Arcy, I Nacewa; J Sexton, E Reddan; C Healy, S Cronin, M Ross, L Cullen (capt), D Browne, K McLaughlin, S Jennings, J Heaslip.

Replacements:R Strauss for Cronin 56 mins; D Toner for Browne 56 mins; H Van der Merwe for Healy 63 mins; I Boss for Reddan 74 mins. Yellow card:I Madigan (Leinster) 77 mins.

Referee: Greg Garner(England).