That sort of careful preparation paid off with the narrow win in Adelaide and what could have been the biggest upset of the tournament in Melbourne.
Meanwhile, Ulster winger Tyrone Howe has arrived in Melbourne as a replacement for the injured Denis Hickie. Howe, who has 10 Ireland caps and toured with the Lions, flew into Australia early this morning.
"He arrived at 6am and trained with the team and he's fine after the long flight," said Ireland team spokesman John Redmond.
Hickie has flown home for surgery on his Achilles tendon after rupturing the ligament against Australia, and he was joined on the plane by Alan Quinlan, who was injured against Argentina.
But coming in the opposite direction are more Irish fans, eager to support their heroes against France.
The success of the team in overcoming Argentina by a point and then pushing Australia so hard has clearly raised Irish expectations.
"There are people talking of coming out from Ireland just for this game," said O'Sullivan in disbelief.
"The whole country has gone crazy at home. The support in Melbourne was incredible and it was a doozy of a game from anybody's angle.
"I knew we wouldn't be supported by Australians playing Australia, but I always felt that support would be with us when we're playing anybody else.
"Next week we'll need it and the gauntlet's down for the boys to put in another big one."
