If last week's win in Ravenhill saw this Leinster team growing up, then this evening's win over Munster sees them perhaps being given the key of the door.
This was a good game of rugby between two teams that were happy to move the ball through the hand. A lively start saw Chistian Cullen look like he was going to continue where he left off last week with his dangerous running.
However, the first opportunity fell to Leinster outhalf David McAllister with a 40m penalty. The young outhalf was to go on to play well, making a couple of darting runs and distributing well, but he didn't catch this penalty well and it fell short and right. With a second penalty, Leinster opted to go for the corner, but solid Munster defence saw them hold out. The respite was only temporary, though, as after 14 minutes Gary Brown showed electric pace to outflank the wide cover before stepping inside the last defender with a neat piece of footwork to go over close to the posts.
Brian O'Meara's convert made it 7-0 Leinster, but it got a lot better for them very quickly. Three minutes later, the ball popped out the side of a Munster recycle on halfway. A couple of flyhacks later and James Norton was dribbling the ball over the line and falling deliriously on it to post Leinster's second try. Another straightforward conversion from O'Meara and Leinster are 14-0 ahead.
The physical intensity was definitely present, but as if to underline the point, Ben Gissing slammed into David Wallace in a maul, much to the returning flanker's annoyance.
The Donnybrook crowd were finding their voice, and it went up an octave when Denis Hickie came on to replace John McWeeney, for his first appearance on a rugby pitch since injuring his Achilles tendon against Australia in the World Cup last November. It wasn't long before he was making an impression, initially with a couple of trademark raking punts off his left foot, but then he was almost in for a try after a neat break and feed from Warner. But he knocked it on. Oops.
An O'Meara penalty on 32 minutes extended the lead still further. Cue the Leinster supporters pinching themselves - sun shining, Hickie back, 17-0 up against Munster and a Saturday night stretching out in front of them. God is good.
But God, if he doesn't actually have a Cork accent, at least has relations in Munster (Keith Wood perhaps), and one knew that this wasn't over yet. While Leinster had been the better side, more accurate in the set pieces and more urgent generally, they had really hit for a couple of scores from deep as opposed to truly dominating. Munster couldn't retain possession through the first half, but it was always unlikely they would stay like this throughout the match.
And sure enough, Munster started to recycle possession better and keep ball in hand. A Burke penalty from 38m after 34 minutes was a little wobbly but made it and Munster had something to get their teeth into at the interval at 17-3 down.
Gaffney's team talk had the desired effect as, despite a Leo Cullen sortie up the line, Munster absolutely dominated the third quarter. Better quality lineout ball launched David Wallace up the centre and better continuity stretched the Leinster defence into conceding a penalty in front of the posts on 44 minutes. Burke recovered from a trademark Quinlan piledriving hit during the advantage phase to slot the kick, reducing the deficit to 17-6. But the momentum was now with the men in red.
Leinster were struggling to get into the Munster half and when they did they were making errors with ball in hand. The Leinster penalty count started to rise and referee Watkins was beginning to tire of it. A forward pass from Burke on halfway wasted a good opportunity to stretch the Leinster defence wide. Leinster's lineout was getting ragged and the momentum was with Munster.
Kidney, the erstwhile coach of the men in red, made a couple of substitutions in a bid to staunch the bleeding, with Costello coming on for his 105th Leinster cap and Ricky Nebbett his first. The former England 'A' prop had a torrid debut, being pinged on his first two scrums for putting his hand on the floor and then driving into the hooker. From the first, Munster looked to maul a lineout and then moved ball up the centre, both phases being halted by emphatic Leinster defence. A turnover resulted in McCullen kicking to halfway to offer some relief to the Blues.
A further change saw Guy Easterby come on for McAllister, with O'Meara moving to outhalf. Nebbett's second penalty concession resulted in a sinbin warning and a Munster lineout close in, from which Munster moved right and back left with the defence stretched. The pivotal moment of the match came when John Kelly floated a beauty of a ball over the top to send Cullen racing in to score. Except, to the astonishment of all, Cullen spilled the pass. It looked backwards and he nearly scored on the recovery, but Watkins adjudged it forward.
With Munster pressure incessant, Leinster were doing well to hold out but another Burke penalty on 62 minutes brought the score to 17-9 and the game was right in the melting pot.
A turned over Leinster lineout and a further penalty had Leo Cullen being explicitly warned about repeated infringing by Watkins. Burke's fourth of five penalty attempts brought the score to 17-12 Leinster.
A Denis Hickie break on the counter led to Leinster's first bout of continuity in the second half after 67 minutes and it was the catalyst for Leinster coming back into the match in the last ten minutes. Another good Hickie counter followed by a clever box ball from Easterby nearly had the flying Gary Brown on the end of it but the touchline beat him.
A break by the prominent Trevor Hogan off turnover ball in the middle of the park stretched the Leinster defence into conceding a penalty that saw Ricky Nebbett sinbinned on 76 minutes. Burke's kick closed the gap to just two, and Saturday night for the denizens of Donnybrook was looking decidedly less promising.
But the 14 men held out well, good bursts from Gissing, Quinlan and Costello sending Leinster deep into Munster territory but inevitably penalties undid the good work.
There was only time for a nasty clash between Sheahan's head and Kelly's hip, necessitating a decidedly groggy-looking Sheahan's departure, before the referee blew up a hard-working Leinster side looked ahead to a deeply satisfying remainder of the evening.
It's only Leinster's second success in ten against their southern rivals, so this side, that has begun to look like it knows how to dig in when the going gets tough and grind out a result, will savour this one a little before getting back down to work.
For Alan Gaffney, a draw from the first three matches seems small reward for some good work going forward. However, there were good performances from Leamy again, and Trevor Hogan was very prominent. And his cavalry are riding over the hill in the shape of the remainder of his international contingent.
Speaking of which, Declan Kidney's got a few interesting decisions ahead of him right now.