Fly-half Felipe Contepomi kicked Leinster to a 21-20 victory over Cardiff Blues in their Magners League clash at the RDS in Dublin.
The visitors narrowly missed out on becoming only the second Welsh region to win at the RDS as an injury-time penalty from Pumas star Contepomi denied them full points. Contepomi struck seven penalties from seven attempts as he drove the defending Magners League champions to a morale-boosting win ahead of next weekend's much-hyped Heineken Cup showdown with Wasps at Twickenham.
Leigh Halfpenny's fourth successful penalty had Cardiff leading 17-12 as the game entered the final quarter. But Contepomi brilliantly held his nerve to boot three crucial penalties in the closing stages, the last of which came after the Blues had regained the lead with a Nicky Robinson drop goal.
These sides duelled out a 16-16 draw at the Arms Park in September and a close game was always on the cards as Contepomi and Halfpenny peppered the posts. Early penalties from the Leinster centre in the 16th and 26th minutes gave the hosts a 6-3 lead, with Halfpenny keeping the Blues in touch.
Bidding to follow in the footsteps of previous RDS winners the Scarlets, Cardiff placed huge pressure on the Leinster pack and after Halfpenny's second penalty, it was no surprise when the visiting forwards helped propel Andy Powell over for an unconverted 30th-minute try. Leinster lorded possession in the closing 10 minutes of the opening half, notching a third penalty through Contepomi.
Michael Cheika's men were close to sniffing out a try but Brian O'Driscoll was just short of the try-line, held up by Tom James' superb cover tackle. The hosts began the second half in determined fashion, with Contepomi continuing to be unerring in front of the posts.
He edged Leinster 12-11 ahead but Wales starlet Halfpenny was showing little sign of nerves at the other end, picking off penalties in the 56th and 66th minutes. However, the introduction of former South Africa international Ollie Le Roux really spurred on the home side and their large vocal support really made their presence felt.
Scrum half Chris Whittaker was also heavily involved in Leinster's resurgence. O'Driscoll again edged towards the whitewash in the 74th minute, only to be denied by Cardiff's resilient defence. With try-scoring opportunities limited, Leinster forced a flurry of late penalties which the classy Contepomi converted.
Two in quick succession had Leinster 18-17 ahead and although Robinson helped himself to an opportunist drop goal, Contepomi had the final say as Leinster closed the gap on league leaders Munster to two points.
Man of the Match Rob Kearney said: "It was hairy stuff towards the end alright, but the high level of competition showed again tonight because everyone had to be on top of their game. Over the last three weeks we have been gradually building and tonight was a fantastic result.
"It was a very tough game and full credit to Felipe for kicking all his goals under pressure. It takes a lot of skill to kick those ones and he was my man of the match, while I also thought that Shane Horgan and Sean O'Brien were superb."
Blues coach Dai Young launched an attack on referee Peter Allan after the game insisting the official had cost them again. "He made a mistake in Munster when (Nicky) Robinson and (Robin) Sowden-Taylor were sin-binned which lost us the game," he told BBC Sport. "The same referee here tonight made another mistake and lost us the game."
"When Nicky Robinson dropped that goal, I thought it was game won really. But I think everyone in the stadium knew there was going to be a penalty coming somewhere. That last penalty, we've looked at it on the video.
"But let's not hide from the fact we've lost a couple of line-outs and the scrum wasn't good. If we had taken that restart (from Robinson's penalty) at the end, we could have controlled the game a little bit better. But we still can't get away from that penalty decision, it was incorrect. That's twice the referee has done it."
Leinster: Kearney, Horgan, O'Driscoll, Contepomi, D'Arcy, Nacewa, Whitaker, Wright, Blaney, van der Linde, Cullen, Toner, Elsom, O'Brien, Heaslip.
Replacements: Fitzgerald for Nacewa (50), le Roux for Blaney (67), Healy for van der Linde (34), O'Kelly for Toner (51).
Blues: Halfpenny, James, J. Robinson, Shanklin, G. Thomas, N. Robinson, Spice, Yapp, T. Thomas, Filise, Davies, Tito, Molitika, Sowden-Taylor, A. Powell.
Replacements: Rees for Spice (64), Jenkins for Yapp (64), G. Williams for T. Thomas (60), Rush for A. Powell (60).
Ref: Peter Allan (SFU)