It meant Leinster leapfrogged Scarlets into sixth place and they will be relieved to claim the win after their 34-23 defeat to Munster last week. Zebre - who remain second bottom - will be disappointed that they fell away once tiredness crept in and most of their good work in the first half was undone in Parma.

Leinster hooker Richardt Strauss returned from a five-month lay-off with a serious hamstring injury to make his 95th appearance for the Irish province.

And it was from his perfectly-weighted lineout throw in the 17th minute that the visitors almost broke the deadlock after a tense, scrappy opening in wet conditions.

He threw to the back and from the resulting drive Leinster's pack was stopped just short, before Noel Reid and Isaac Boss - whose effort was ruled out by the television match official - also failed to scramble it over the whitewash through a melee of bodies.

Leinster did have something to show for that period of sustained pressure, though, as Marco Bortolami was sent to the sin-bin.

But it was Zebre who grabbed the initiative, despite being down to 14 men, as Orquera kicked over a penalty to make Leinster pay for their over-eagerness at the breakdown.

As if woken from their slumber Leinster, who were aiming to avoid back-to-back defeats in the PRO12 for the first time since 2010-11, got on the front foot and tried to make their man advantage count.

Zebre's defence held firm though, as the visitors struggled to make inroads against their impressive blitz tactics.

By contrast Leinster were almost caught napping when Zebre surged forwards and only a slight knock-on from Giulio Toniolatti scuppered the chances of seeing the unlikely figure of lock Quintin Geldenhuys sprinting clean through on the left wing.

Madigan had a clearance kick charged down and hit the post with a simple penalty attempt as Leinster began to show signs of panic, but the 23-year-old did split the posts at the second attempt to level up just before the interval.

Shortly after the break the Ireland Under-20 international eased Leinster's nerves further with a superb solo dart to scythe through Zebre's unusually dog-legged defence and touch down under the posts.

It was a moment of individual brilliance and Madigan added the extras, before adding another penalty in the 50th minute to suddenly put Matt O'Connor's side in control at 13-3.

The hosts surged forward with plenty of effort and brute force but it was clear that they just had no-one capable of finding the spark to ignite them like Madigan had for Leinster.

McGrath, on for Boss, then made the most of Zebre's tiredness to dart over round the fringes in the 69th minute and fellow replacement Gopperth kicked the conversion to complete the scoring as Madigan received treatment after a massive hit from George Biagi.