Munster fly-half Ronan O'Gara booted all Ireland's points in difficult conditions with heavy rain dampening ambitions to extend their attacking game into the second half.
It was ugly but effective with the gameplan after the break, when the wind was with the Irish, grinding a gutsy but limited Scotland outfit into the Dublin turf.
Now Brian O'Driscoll and co travel to Twickenham hoping to land their first championship title since 1985 and O'Sullivan is also eyeing a second Triple Crown in three years.
"We're in the situation we wanted to be in at this point," said the Ireland head coach.
"We said after beating Wales we were very happy but this result has put us in the position to win and that's why nothing mattered until the final whistle.
"We're still in charge of our own destiny. We go to Twickenham with a Triple Crown there for the taking as well. That's a nice place to be after four games in the championship.
"We feel like we achieved something in beating a very good Scotland team. Now we will circle the wagons and start setting our sights on Twickenham."
Another gear will have to be found if England are to be unseated next Saturday, the last match of the Six Nations, but they will travel to Twickenham high in confidence.
"We knew how physical they were going to be and given the conditions it was never going to be an expansive game," said skipper O'Driscoll.
"The impacts were big because a lot of the rugby was played in close quarters. Their defensive record meant they weren't going to be easy to break down.
"If their frontline missed any tackles then their scramble was excellent. We adapted our gameplan and the strategy worked very well. In the second half I felt we played very smart rugby.
"I felt we played all the rugby and alas they kept within six points of us to the death, but we dominated the game. Scotland are a team on the up.
"I said to the boys on Friday night it's likely to be a one-score game and that's how it turned out."