After a stuttering first half of the campaign as they adjust to life without Brian O’Driscoll, 2015 has brought much-needed momentum for Matt O’Connor’s side.
A third straight Pro12 crown looked unlikely earlier in the season but this victory over a stubborn Blues side, and the win over Ulster at the RDS the previous week, will no doubt have caught the eye of their rivals.
There were plenty of obstacles to overcome in Cardiff, not least the flight over the Irish Sea to the Welsh capital on Friday night. Two failed landing attempts at Cardiff Airport forced a diversion to Bristol and added three hours to their journey.
It was the sort of scare that could easily have led to Leinster’s first defeat against the Blues since 2007 but, despite O’Connor making 11 changes from the side who beat Ulster, they showed they are not going to give up their Pro12 crown without a fight.
“It’s a massive victory,” said prop Marty Moore, who made his first start after four months out through injury. “We’ve had a couple of tough games but against Ulster we started to build positivity within the squad and we want to take that forward.
“We feel we are turning a corner, there is always pressure but we know when we get our basics right, we can be a very good team.
“The last few months we’ve probably had as many boys out injured as in the playing squad but to see the young lads come in and do so well gives us great belief. Last year we crashed out of Europe but went on to win the league but this year we want to win both.”
A league and European Cup double would be a huge ask but O’Connor was delighted with the way his charges fought back to claim maximum points against the Blues.
Cardiff have been improving under New Zealander Mark Hammett but on this occasion he was let down by another former All Black, lock Jarrad Hoeata, who was shown a first half red card for a dangerously high tackle on Rob Kearney. It left the Blues with a mountain to climb having already lost influential flanker Sam Warburton to an eye injury after 12 minutes.
Hammett’s side defended resolutely but a second card after half-time, this time a yellow for first-half try-scorer Manoa Vosawai, allowed Leinster to take control.
Wasps-bound Jimmy Gopperth was outstanding at outside half and he must now be in the driving seat for a starting spot against Castres. He provided a timely reminder of his worth with a 40-metre burst in the opening minute to put centre Noel Reid over for the game’s opening try before scoring a crucial try himself 15 minutes into the second period to bring Leinster back to within one point.
Tries from Gopperth’s impressive half-back partner Luke McGrath and replacement prop Tadhg Furlong secured the bonus point to set them up nicely for the visit of Castres.
Leinster coach O’Connor said: “Another win is important building into Europe and we are pretty happy with how things are going.
“There’s an awful lot to play for next week.”
Leinster could also be boosted by the return of captain Jamie Heaslip, who was forced out of the Ulster game early on with a shoulder injury and missed Saturday’s trip to Cardiff but should be available this weekend.
Scorers for Cardiff: Tries: Vosawai; Conv: Anscombe; Pens: Anscombe (2).
Scorers for Leinster: Tries: Reid, Gopperth, McGrath, Furlong, Conv: Gopperth.
CARDIFF BLUES: J Tuculet; A Cuthbert, C Allen, G Evans (A Thomas 50), L Amorosino; G Anscombe, T Knoyle (L Williams 63); G Jenkins (c), K Dacey 6 (M Rees 33), A Jones (T Filise 63); L Reed, J Hoeata; Jo Turnbull (M Normandale, 78), S Warburton 6 (M Vosawai 13), J Navidi.
LEINSTER: R Kearney; F McFadden, B Te’o (D Fanning 63), N Reid, D Kearney; J Gopperth, L McGrath (E Reddan 63); M Bent (J Hagan 55), S Cronin (R Strauss 57), M Moore (T Furlong 50); M McCarthy (B Marshall 69), K Douglas; D Ryan (J Flier 57), J Murphy, J Conan.
Referee: Neil Patterson (SRU).