These are worrying times for the Ospreys, who earned a bonus point but failed to show any real attacking flair despite the introduction of British & Irish Lions Lee Byrne, Shane Williams and Alun Wyn Jones.

Both sides swapped penalties during the opening skirmishes. Leinster opened the scoring with a penalty through Sexton after Marty Holah failed to release at a ruck and three minutes later the Welsh side were back on level terms through a James Hook kick following an offside decision.

The Ospreys got themselves in some trouble in their own 22 but got a penalty decision in their favour at a scrum in the shadow of their posts.

But crossing in their own half saw Leinster get back into the lead with a second Sexton penalty on 15 minutes.

The Ospreys turned defence into attack and won a penalty as Shaun Berne failed to release at a ruck.

But Hook failed to convert his attempt from 35 metres out on the right.

A golden chance of an Ospreys try went begging when Jamie Nutbrown made a break from a scrum on the 22 but could not find wing Tommy Bowe with his long pass out to the right.

But the Ospreys pressure continued and built into a try scored by Jerry Collins, his first for the region, as the home side mauled a line-out from five metres out over the line.

At 8-6 down Leinster had two chances to regain the lead but Sexton missed penalty goal chances on 30 and 35 minutes.

The Ospreys looked in real trouble just before half-time when they had Collins (violent play) and Duncan Jones (professional foul) sent to the sin-bin in the space of three minutes.

However, they managed to hang on to their two-point advantage until the break.

As in the first half Sexton and Hook swapped penalties, but it was Leinster who built up a head of steam in the final quarter despite the Ospreys bringing on Mike Phillips, Williams and Alun Wyn Jones.

A mistake by Williams allowed Leinster to get in an attacking position from where full-back Isa Nacewa was able to slot over a drop-goal.

And two further Sexton penalties on 75 and 80 minutes gave Leinster enough of a cushion to survive until the final whistle.