Wales dominated the opening twenty minutes when Mark Jones went over to score after eight minutes, but that proved to be the visitors only score as the Irish defence began to function.
After just twenty minutes, Wales inspirational outside half Stephen Jones fell awkward in a tackle forcing him to be substituted by the returning Gavin Henson who had only played one game in the last eight weeks following a lengthy suspension. That was a telling moment in the game. Ireland settled in to a good defensive routine and began to take control of a game as they racked up 31 points without reply.
"The key for us was to defend well and make Wales work for every yard they got," O'Sullivsan said. "I thought we played well enough to win that game. Our defence was outstanding, other than that one Wales try which was a nice little kick over the top which bounced away from Andrew.
"I thought we defended really well. They had to work very hard for any gain-lines they got and we turned them over quite a good few times, or else they had really slow ball to work off.
"Once you slow the football down, the defence is in the ascendancy and that's what we did. We stopped Wales getting into their own game and that was very telling."
O'Gara opened the Irish scoring with a penalty on seventeen minutes, and his fellow Munster teammate David Wallace was the first Irishman to cross the line on twenty-eight minutes after Wales's defence was breached following sustained green bombardment. O'Gara converted the try to leave the scores at 11-5 in favour of Ireland at the half time interval.
Ireland stepped up in the second half, with Shane Horgan and Peter Stringer scoring tries, and O'Gara completing the scoring with the boot.