Leinster moved to within three points of RaboDirect PRO12 leaders Munster with a 31-8 win at Zebre.
The champions ran in four tries to pick up a bonus point in Italy.
They eventually found some rhythm after Dries van Schalkwyk had touched down for the hosts early on, driving his way over from close range.
Leinster's response came from John Cooney, coming in off the back of the scrum to split two defenders. Jimmy Gopperth added the conversion.
A Gopperth penalty arrived before the break with a second try being posted after it, with Noel Reid racing clear, leaving Gopperth with a simple conversion under the posts.
Zebre responded with a penalty from Kelly Haimona, but three-point contributions were not good enough and Zane Kirchner showed them how it should be done as he crashed on to an offload for a try, with substitute Ian Madigan converting.
A fourth try then rounded things off with Darren Hudson sidestepping over the line with seconds remaining, with Madigan again on the spot with the two points.