Rob Kearney's try helped Leinster to a famous 16-15 victory over provincial rivals Munster in the Magners League on Friday.
Ronan O'Gara kicked all of Munster's points but his rival for the Ireland number ten jersey Jonathan Sexton had the final say at Thomond Park as his Leinster side prevailed.
Having missed a penalty just two minutes earlier, Sexton held his nerve to convert a 66th minute kick and drive Leinster to their first win at the Limerick venue since 1995 and their third successive triumph over their arch rivals.
It has given Michael Cheika's men a seven-point advantage at the top of the Magners League, and serious momentum ahead of next weekend's Heineken Cup quarter-final showdown with Clermont Auvergne.
The result owed much to Leinster's watertight defence and territorial dominance as the game wore on, with full-back Rob Kearney's late first half touchdown proving to be the only try on the night.
O'Gara, Munster's captain in the absence of the injured Paul O'Connell, had a 100% kicking return with five successful penalties, but it was not enough as Sexton and Fergus McFadden landed three penalties between them and the former converted Kearney's try.
Having recently lost his starting place in the Ireland team to Sexton, O'Gara's eagerness to impress was seen in the opening seconds when he charged down his opposite number.
In a raucous atmosphere, Munster seized the early initiative with an O'Gara penalty punishing a binding offence from CJ van der Linde, and the latter's Springbok colleague Jean de Villiers featuring in a thrilling right wing raid.
Munster were varying their attacks well and when Leinster captain Leo Cullen saw yellow in the 14th minute for a deliberate knock on, O'Gara gave the hosts a deserved 6-0 lead.
However, the numbers were evened up three minutes later as Donncha O'Callaghan was sin-binned for slapping the ball out of Shane Jennings' hands at a ruck, and Sexton landed the resulting penalty for Leinster's opening points.
The first half was largely free-flowing but there was a typically hard-edged element to this inter-provincial clash and a needless check by Girvan Dempsey on de Villiers allowed O'Gara make it 9-3.
Leinster hit back with a side-stepping break from Gordon D'Arcy and only frantic defending - Ian Dowling stopped Kearney just short of the try-line - kept the visitors out.
The attack did produce a second successful penalty, struck by McFadden as Sexton received attention.
O'Gara replied with another fine drive from the left, as Leinster were penalised for not retreating, and it looked to be advantage Munster as Sexton pushed a late penalty to the right and wide.
However, Leinster engineered a smash-and-grab try in the dying seconds of the half as a chip through from Isa Nacewa bounced awkwardly for Tomas O'Leary and Doug Howlett and the advancing Kearney gathered it to crash over in the corner.
Sexton silenced those in the crowd who had been jeering him with a tremendous conversion from wide out, handing Leinster a 13-12 buffer for the break.
Leinster dictated play in the opening stages of the second period but O'Gara shot Munster back in front, after Nathan Hines was sin-binned for a dangerous tackle on Dowling.
On the hour, Leinster went through a series of phases in the Munster half and worked two penalty chances for Sexton, the second of which he slotted from the left.
The Leinster out-half snatched at a 73rd minute drop goal as he tried to extend Leinster's lead, and the tension grew as Munster marched towards the visitors' 22, with the tireless Alan Quinlan leading the charge.
However, a knock on between O'Gara and Lifeimi Mafi undid all the good work and Leinster, with Nacewa almost getting through for an intercept try, were able to soak up the pressure in midfield and see out a deserved win.
For Munster:Pens: O'Gara 5
Pens: Sexton 2, McFadden
Munster: 15 Paul Warwick, 14 Doug Howlett, 13 Lifeimi Mafi, 12 Jean de Villiers, 11 Ian Dowling, 10 Ronan O'Gara (c), 9 Tomas O'Leary, 8 David Wallace, 7 Niall Ronan, 6 Alan Quinlan, 5 Mick O'Driscoll, 4 Donncha O'Callaghan, 3 John Hayes, 2 Jerry Flannery, 1 Marcus Horan.
Replacements: 16 Denis Fogarty, 17 Tony Buckley, 18 Neil Williams, 19 John Coughlan, 20 Peter Stringer, 21 Tim Gleeson, 22 Sean Deasy.
Leinster: 15 Rob Kearney, 14 Girvan Dempsey, 13 Fergus McFadden, 12 Gordon D'Arcy, 11 Isa Nacewa, 10 Jonathan Sexton, 9 Eoin Reddan, 8 Jamie Heaslip, 7 Shane Jennings, 6 Nathan Hines, 5 Devin Toner, 4 Leo Cullen (c), 3 CJ van der Linde, 2 John Fogarty, 1 Stan Wright.
Replacements: 16 Bernard Jackman, 17 Cian Healy, 18 Malcolm O'Kelly, 19 Stephen Keogh, 20 Paul O'Donohoe, 21 Shaun Berne, 22 Eoin O'Malley.
Referee: Romain Poite.