"This first weekend has shown that this is truly a Six Nations Championship," he said. "We have seen the underdogs doing well. Scotland deserved to win in Paris and it was something of a surprise that Wales beat England.
"Now today Italy have played really good rugby. They dominated possession in the first half and held on to the ball for long periods throughout the match.
"We had just three attacking opportunities in the first half and scored from two of them, but in general we did not clear our lines; we seemed to struggle with the Mitre ball. And too often we found ourselves in possession but out of attacking range, camped in our side of the pitch. It was not until the second half that we were able to play for field position, but it still took us something like 70 minutes to wear down this Italian team."
O'Sullivan insisted it was no more than had been expected. "We knew that Italy would push us really hard," he said. "I am just pleased that we won the game. This weekend proves that on any given day any team can win. The health of squads will affect the tournament as it goes on. Injuries to key players, such as we have, could have an adverse impact on teams' performances over the next few weeks."
Ireland's hooker, Shane Byrne, added: "There was no jumping around in celebration afterwards. We know there is a job to do. Over the next few days we have to correct the mistakes we made."Reuse content