They managed just one try in cold conditions in Dublin, through Sean Cronin, but showed their defensive ability, particularly through the impressive flanker Josh van der Flier.

And in the end they were able to hold on as Ulster couldn't find a way through in the second half, which ended scoreless.

The home side started the better and led after just five minutes thanks to a Johnny Sexton penalty, while Paddy Jackson was off-target with his first attempt soon after.

Jackson did level matters on 13 minutes, but Leinster were looking the more dangerous side, and on a couple of occasions they were close to going over.

They looked sure to score midway through the half after a long period of possession in the Ulster 22. When the forwards couldn't quite bludgeon their way over, Leinster turned to their backs, but an uncharacteristically poor pass from Isa Nacewa gave Zane Kirchner no chance, and the Springbok knocked on out wide.

Leinster were then dealt a blow when Luke McGrath picked up what looked to be a serious knee injury and had to be replaced by Eoin Reddan.

Dominating possession, Leinster turned down an easy shot at goal to kick for the corner, only to see Robbie Diack steal a second successive lineout.

Cronin was the guilty party with the throw, but soon made up for it when he emerged from the pile of bodies to score the game's first try.

After Ulster were caught offside in midfield, Leinster this time won the lineout, and set the up the rolling maul perfectly. Ulster had no answer and Cronin was the man at the back of the drive who claimed the try. Sexton missed the conversion but the home side led 8-3 at the break.

It was scant reward for Leinster's territorial dominance, and they managed to maintain that advantage in the early stages of the second period.

As had been the case for much of the first half, they struggled to turn it into points though, and Ulster eventually got some territory of their own.

Like Leinster they were struggling to take their opportunities, and one incursion into the opposition 22 ended with a penalty for the home side when Marty Moore got over the ball before the Ulster support.

It was scrappy stuff with neither team really able to find a way through as the half remained scoreless before a long delay when Noel Reid appeared to pick up a serious leg injury which saw him depart minutes after coming on.

And although Ulster had their chances late on, there was no way through.

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