First-half tries from Jack McGrath and new captain Isa Nacewa ensured Leo Cullen’s side enjoyed a 15-3 half-time lead.
With Treviso unable to muster a fightback after the break - this was their 13th straight Pro12 defeat - further tries from Jack Conan and Ben Te’o ensured that the eastern province would be taking home bonus point.
Just under a year ago, the sides had drawn 24-24 here, and Leinster had won just one of their previous eight away league games, but this never looked like being anything other than a blue procession. In the third minute, they opened the scoring as a good series of ball- retention - with Luke Fitzgerald injecting some dynamism - ended with Seán Cronin offloading to McGrath, who crossed for his seventh Pro12 try. Jonathan Sexton - making his return to Leinster colours after a spell with Racing Metro - added the extras and though Jayden Hayward got Treviso off the mark with a penalty, they couldn’t make any further inroads into the deficit.
The hosts had a great opportunity to inflict pressure on their visitors when Sexton was yellow-carded for a late tackle on Hayward in the 13th minute. Leinster held out, though, with debutant lock Hayden Triggs, Dave Kearney and Nacewa making vital contributions. In addition, a kickable penalty was turned down by the Italians but they couldn’t make the most of the resultant lineout maul.
It was actually after Sexton’s return that Treviso went closest to a try but a rolling maul which get them over the line in the corner was deemed not to have resulted in a try, according to the TMO.
While Leinster did have a slight worry when Fitzgerald was forced off with a shoulder injury, they moved seven points clear as Fergus McFadden converted a penalty and, just before half-time, they gave themselves more of a cushion.
From a lineout, Sexton produced a perfect cross-field kick which ended up in Kearney’s hands and he fed Nacewa, who touched down for his fourth try in as many games. McFadden couldn’t convert, but 12 points was a healthy interval lead. Early in the second-half, Treviso again applied pressure, with Tommaso Iannone and Simone Ragusi prominent, but this time Rhys Ruddock was the player to force an attacking mistake and on 56, Leinster mae them pay as Conan crossed following good hands from Jordi Murphy and Nacewa after a fine burst by Fitzgerald’s replacement Noel Reid.
Again, McFadden failed with the conversion attempt but, after Treviso’s Ludovico Nitoglia was sin-binned for a deliberate knock-on, centre Te’o ensured further punishment as he broke from deep and confirmed the fourth try and extra point. Leinster’s next outing is at home to league leaders the Scarlets - whom they trail by six points - next Friday night (7.35pm).
Elsewhere, French side Grenoble - coached by former Leinster and Ireland hooker Bernard Jackman, recorded a 33-29 Top14 win over European champions Grenoble.
Hayward, Nitoglia, Pratichetti, Christie, Ragusi, McLean, Gori, Zanusso, Giazzon, Harden, Fuser, Paulo, Minto, Zanni, Steyn.
Iannone for Pratichetti (41), Smylie for Gori (68), de Marchi for Zanusso (51), Bigi for Giazzon (53), Ferrari for Harden (51), Montauriol for Fuser (58), Barbieri for Minto (58). Sin Bin: Nitoglia (59).
Tries: J. McGrath, Nacewa, Conan, Te’o. Cons: Sexton, McFadden. Pens: McFadden.
Nacewa, McFadden, Te’o, Fitzgerald, D. Kearney, Sexton, Reddan, J. McGrath, Cronin, Furlong, Triggs, McCarthy, Ruddock, Murphy, Conan.
Healy for J. McGrath (49), Strauss for Cronin (49), Moore for Furlong (49), van der Flier for Triggs (65), Toner for McCarthy (63). Not Used: L. McGrath, Marsh, Reid. Sin Bin: Sexton (11).
Andy Brace (Ireland).