The Irish remain on course for the RBS 6 Nations championship title and a Triple Crown after the triumph but the deteriorating conditions made for a long afternoon in Dublin.

Ronan O'Gara kicked all the points and it was hardly the sparkling send-off scripted for Lansdowne Road's last RBS 6 Nations match before undergoing redevelopment next year.

But O'Sullivan was delighted Frank Hadden's rejuvenated Scotland had been dispatched and felt his side's tactics were spot on.

We talked in the week about having an impact in the first 10-15 minutes and getting the crowd behind us, he said.

The weather came in on top of us and we knew from then it would be a tight one-score game. It was a case of rolling up your sleeves and getting in the trenches.

Credit to Scotland - they were in the game for 80 minutes and fought for every yard. People might describe it as an ugly win but I thought it was a very good win.

We used the appropriate tactics to get the result. I'm very proud of the team.

If you're a rugby purist that was a bloody good Six Nations match played in very poor conditions. You don't get to choose the conditions, just how you play.

Ireland threatened to cross on several occasions but their execution frequently let them down and it became increasing difficult to score as the rain continued to fall.

O'Sullivan admitted on occasions they were too ambitious given the conditions but in his side's defence cited how close they went to breaching the whitewash.

Three or four times we were an offload away from scoring a try,'' he said.

If one of those had come off I think we would have been in under the posts which would have given us a little bit of breathing space and taken a lot of the pressure of us.

When they don't come off it's easy to say we should have stuck it up our jumper. But at times maybe we forced it a little bit and tried to play too much rugby.

The guys out there have to make the decisions and had one of them come off it would have changed the game. Over the 80 minutes we started the way we intended to go on.

O'Sullivan felt a strong defence and flawless line-out underpinned the victory.

The bedrock of our success was our lineout - we were top draw on our own ball and we caused them a huge amount of problems on their ball, he said.

Our defence was superb and we were very hard in the tackle. Their defence was magnificent as well.