A healthy half-time lead had just been whittled away and when Dan Parks kicked the Cardiff Blues into the lead on 64 minutes the sense of déjà vu was palpable.
Joe Schmidt was forced to withdraw Ireland captain Brian O’Driscoll under the player welfare scheme, while his own skipper, Shane Jennings, went off injured leaving a callow side on the field. But they stepped up, led by Isa Nacewa and Jamie Heaslip, and scored 14 points without reply to win with a bonus point.
Cian Healy made a try for Fergus McFadden, before young fly-half Ian Madigan – a late replacement for Jonny Sexton, who pulled his quad in the warm up – scythed through the Blues rearguard for a wonderful solo effort to cap the night.
After his first win as coach Schmidt expressed satisfaction at seeing his youthful side recover.
“It’s a relief to get through,” Schmidt said. “The icing on the cake was that it was young Madigan who finished it off and managed to snaffle a bonus-point at the end. That was fantastic.
“I’ve got a lot of confidence in the younger players. If they don’t show that confidence, they don’t get an opportunity and they don’t know how to close out a tough game – or chase a tough game as it was in the end.
“It was great for Mads, on reflection. I was a little bit worried we lost Jonny so late. He had pretty much run the team for the whole week. To lose that at the front end of the warm-up, let alone the game, was a bit nerve-wracking, but not for young Ian.
“He just goes ‘Aw, fine, yep, great, I’ll take it from there,” and he took it not too badly.
“I think the previous week probably did us a little bit of good. Some of the young guys that were there learned a little bit from it. I thought the support they got from Isa Nacewa and Luke Fitzgerald was superb. They gave us a really strong influence from the back.
“That allowed the three young guys in front of them to have confidence. All they really wanted to do was close them down and look after the ball when they carried it.”
Leinster had exploded into this game with Isaac Boss creating an opening for Jennings, before sublime hands from Richardt Strauss and a burst from Luke Fitzgerald put the inspired Nacewa over to make the score 14-0 after just ten minutes.
The boots of Nacewa and Parks kept the scoreboard ticking over, giving Leinster a 20-6 half-time lead. But in the third quarter the Blues, wearing hideous pink, moved ominously through the gears and played some excellent rugby to create tries for Bradley Davies and Richie Rees.
Parks edged his side into a three-point lead, but Leinster checked the momentum and turned it in their favour to delight of the 15,890 crowd.
While there is much to work this week ahead of the trip to Treviso one aspect that particularly pleased everyone in blue was the scrum, as Mike Ross in particular gave the inexperienced Cardiff front row a torrid night.
“We certainly profited from it,” Schmidt said. “It must have been five or six (penalties), and maybe two or three against us, but I thought we were unlucky not to get another two or three turnovers.
“We certainly were dominating. Both Heinke van der Merwe and Mike Ross were going very, very well and Richardt is growing in confidence. It’s not so much a (scrum) crisis, just that we need to have the depth.
“From our perspective, we felt we were really dominant at scrum-time and maybe didn’t get the reward for that a couple of times.
“We are not looking to re-invent the wheel. We are looking to improve the detail of what we do. And evidently, when there are a lot of players coming in and out, it is the best remedy to keep things nice and simple and try to do those simple things as well as we can.”
LEINSTER: L Fitzgerald; S Horgan (D Kearney 50), B O’Driscoll (E O’Malley 62), F McFadden (B O’Driscoll 74-79 – blood), I Nacewa; I Madigan, I Boss (E Reddan 54); H van der Merwe (C Healy 62), R Strauss (J Fogarty 56), M Ross; N Hines, E O’Donoghue (M Galarza 79); S O’Brien, S Jennings (capt) (D Ryan 62), J Heaslip.
CARDIFF BLUES: C Czekaj; R Mustoe, C Laulala (G Evans 73), D Hewitt, T James; D Parks, R Rees; T Davies (F Filise 35), T Rhys-Thomas, S Andrews (J Yapp 50); B Davies, D Jones (J Down 58); M Paterson, S Warburton, X Rush (capt).
Referee: A Macpherson (Scotland).