The stakes are high for Pool C's most eagerly-awaited encounter between Ireland and Australia on Saturday, with a place in the quarter-finals guaranteed for the winner.
Australia were not convincing in their 32-6 win over Italy, while Ireland were made to work hard before beating the USA 22-10.
The special guest on this week's Rugby Club was Ireland and London Irish lock Bob Casey.
And he believes that Ireland must go back to their strengths if they want to upset the Tri-Nations champions.
"Ireland are not playing great at the moment so I don't think we can be too flash," said Casey. "I think we need to play to our strengths and hope that (Jonathan) Sexton brings his kicking boots.
"Against the USA our scrum was strong, our lineout was strong and I hate to be boring but our line out drive was very effective. Australia struggled with that against Italy and gave away a couple of penalties."
Most of Ireland's senior players have not been at their best but Casey - who has six international caps - was full of praise for the in-form Paul O'Connell.
"There was an article about how he decided to strip down from 118kg to 110 and he is one of our senior players who is on form - not many of them are right now," added Casey.
"He is ruling the skies with this lineout and his ball off the top is fantastic. That is what we want to see more off.
Casey was also concerned with the number of turnovers Ireland conceded against the USA and says a team with the likes of Will Genia, Kurtley Beale and Quade Cooper will make Declan Kidney's men suffer.
However, he also believes that Ireland can exploit Cooper's perceived weakness - his defence under the high ball.
"The worrying thing is that Ireland turned over the ball nine times in the first half against the USA, if we do that (against Australia) then the Wallaby back line will punish us," explained Casey.
"Ireland must try and expose Cooper under the high ball and get Tommy Bowe running onto him. Bowe is an old Gaelic footballer and is great in the air, he will really attack that ball."