Leo Cullen’s Leinster just about escaped with a bonus-point victory over Zebre Parma in the opening round of the United Rugby Championship at Stadio Sergio Lanfranchi on Saturday afternoon.

Rhys Ruddock led the way with a brace of tries to go beside those of Luke McGrath, Jason Jenkins and Dave Kearney in an entertaining ten-try tussle.

The kick from Luke McGrath and the chase by Rob Russell caused a spill which Leinster’s scrum turned into a penalty.

Ross Byrne looked to the corner and Ronan Kelleher’s throw found Ross Molony soaring at the lineout, the hooker unable to ground the ball over the line.

It wasn’t long before out-half Byrne was popping the ball up off the floor and Charlie Ngatai was shooting through the middle.

Luke McGrath spotted a hole on the fringe of a ruck for the first try, converted by Byrne in the sixth minute.

Straight away, Leinster looked to access the wider channels, mostly through timing the pass into space, Jamie Osborne showing up well at thirteen.

For all of that, Zebre were holding firm in defence. Out-half Tiff Eden kicked them forward and Pierre Bruno almost cracked the cover, while Osborne was alert in taking down Erich Cronje.

A lovely rumble and offload by Kelleher allied to a hard-marching maul put Leinster deep inside the 22 where not even the best pass of Rhys Ruddock’s career could not unlock Zebre’s disciplined defence, led by loose forwards Luca Andreani and MJ Pelser.

An accurate ball by Kelleher to Jason Jenkins at the rear of the lineout was taken at full tilt by  Ruddock for a well-worked try, converted by Byrne in the 21st minute.

The impressive work of locks Molony and Jenkins in the loose was good for getting beyond the gain line.

Zebre were struggling with the maul. Captain David Sisi was binned for being offside before a patient maul ended with Ruddock pouncing for his second, Byrne converting for 21-0 in the 27th minute.

Then, the home side produced a magical move in which Eden, Bruno and Enricho Lucchin connected to put full-back Richard Kriel over on the left on the half-hour.

The injection of confidence was apparent as Eden kicked crossfield to the right where wing Bruno caught, chipped and gathered for a tremendous try in the 33rd minute, harvesting a remarkable 10 points in the time Sisi sat in the bin.

Ed Byrne squeezed a scrum penalty and Leinster nabbed the bonus-point fourth from a pre-planned move from five metres out, Jenkins claiming a try on his debut for Byrne to kick the extras for 28-10 at the break.

The Italians came out firing, taking the ball on with authority until Leinster’s organisation caused a knock-on in midfield.

The excellence of Max Deegan at a ruck and a subsequent maul did not completely cover-up how Zebre were dictating matters.

From a lineout, Eden flashed a pass right-to-left for Simone Gesi to just about squeeze in at the left corner for 28-15 in the 48th minute.

It was game-on when the Parma club played heads-up rugby for openside Pelser to bump a defender on his way to the posts for their fourth try, Eden’s conversion making it a one-score game in the 55th minute.

The set-piece was proving Leinster best avenue forward. Predictable carries close to the line opened up the space for Ciaran Frawley to find Dave Kearney for another five points on the hour.

The Irish province was able to keep Zebre thinking about defence until a high tackle allowed Eden’s penalty to put them in a bind.

The presence of Lucchin on the ball created a doubt for Franco Smith to power between defenders for Eden’s conversion to make it 33-29 in the 69th minute.

It was white-knuckle time as Zebre came hunting the lead for the first time, shifting the ball from side-to-side in search of a gap.

The cohesion in Leinster’s defence kept the attackers in front of them, Alex Soroka, Brian Deeny and Will Connors making an impact from the bench to hold on to the final whistle.