Rory Clegg made an immediate impact on his return to Glasgow

Glasgow's stand off Rory Clegg, newly returned from a spell in France with Oyonnax, was their hero kicking two penalties in each half. Isa Nacewa kept Leinster in touch with his two first-half penalties.

Glasgow kicked off on an improved Scotstoun surface after the mid-winter postponements, but it was the visitors who took the lead with a penalty in just the third minute from Nacewa.

In the 14th minute a penalty from Glasgow's Clegg, after a Leinster kick out on the full had given them position, brought equality.

Three minutes later Clegg eased Glasgow ahead with his second penalty success.

The half consisted of long periods where each side in turn had prolonged periods of possession with little ground gained.

However a bright kick and take on the left wing by Leinster's Dave Kearney should have brought a try when an overlap was created on the right. However stand-off Cathal Marsh passed behind his troops and into touch.

Leinster did equalise with a penalty from Nacewa, but the winger closed the half by missing a straightforward penalty chance, so the teams went in with the score tied at 6-6.

Warriors squad was being stretched to breaking point when Peter Murchie became the third Glasgow back to be forced off - after Rory Hughes (rep. Glenn Bryce) and Sam Johnson (rep. Nick Grigg) had departed earlier - prompting a reshuffle in the home ranks as the sides changed ends.

Scrum-half Ali Price replaced the skipper, with Grigg moving to centre, Grayson Hart to the wing and Bryce shifting back to full-back.

Glasgow restarted the better, trapping Leinster in their 22, with Clegg easing them back into the lead with a 50th minute penalty which he extended seven minutes later with his fourth success.

The Glasgow pack was soon forced to improvise when Simone Favaro went off injured and young hooker James Malcolm was sent into the front row with Fraser Brown moving to openside.

Leinster ramped up the pressure but the home defences held firm.

Then, with five minutes left, a long penalty allowed Leinster to establish themselves in the home 22 and the chance to win the match. But they were repulsed until Peadar Timmins was penalised for side entry and the Warriors secured what could be a vital four points.