Jack Conan marked his Leinster debut with a try-scoring man of the match performance as the reigning RaboDirect PRO12 champions saw off Cardiff Blues 34-22 to go back to the top of the table.
Conan, a member of the club’s Academy, dotted down alongside returning Richardt Strauss before efforts from Gareth Davies and Kristian Dacey pulled the Blues back to within five points, 17-12 at the break.
But Leinster came again in the second half with Michael Bent and Eoin Reddan securing the bonus point win, while Dan Fish added the third try for the Blues, who have now won just once in their last eight league games.
Looking to maintain their impressive record against Welsh clubs, Leinster got off to the perfect start with Ireland Under-20s number eight Conan dotting down inside three minutes.
There was a touch of luck about it, with the ball popping out of a Leinster scrum close to the Blues try line, but seizing the opportunity, Conan pounced to cross, with the TMO confirming the score.
Jimmy Gopperth split the posts for the extra two points before the visitors maintained their pressure on their opponents.
And when another solid attacking move saw them fall just short in front of the posts, the ball was recycled out wide for Strauss who comfortably slid over in the corner.
Gopperth again added the conversion from the touch line to deservedly fire the hosts further ahead just short of 20 minutes.
The 14-point cushion would not last for long however as the Blues replied by going straight back up the other end to score a try of their own, after superb individual work by Davies.
Owen Jenkins did well to keep the move alive on the near touch line before the ball was recycled out to Davies, who sold a dummy before breaking through the line under the posts to leave himself an easy conversion.
Gopperth extended his side’s lead to ten points with a 28th minute penalty, although Blues had a great chance to notch up their second try of the game after Robin Copeland broke through the tackle before charging for the line.
But he failed to offload to the overlapping Josh Navidi and instead was tackled by the Leinster defence with the chance gone.
The Blues could not be criticised for not making the breaks in the game though with full back Fish picking up the ball in his own half before sweeping up field.
The Blues maintained their push, and after Tom Denton had been sent to the bin, the hosts powered over in the corner with Dacey getting the final touch, Davies missing the conversion.
With a man advantage, the early second-half pressure was coming from the Blues with Davies’ kick reducing the difference to two points on 45 minutes.
But with a full compliment back on the pitch, the reigning champions reasserted themselves, Gopperth adding a 47th minute penalty before replacement back row Rhys Ruddock powered towards the line five minutes later with Dent diving over.
And the bonus point try was secured on 56 minutes when Reddan seized the ball at the bottom of the ruck before spotting the gap and running in under the posts to set up an easy conversion.
The Blues were not throwing in the towel though, Davies again the creator with a decisive break before Fish dotted down with 20 minutes remaining for 34-22.
But it would be their last score of the night, although there was still time for Gopperth to blot his copy book with a late missed penalty.