An old fashioned ambush awaits Australia at Telstra Dome on Sunday as the Irish prepare to stifle any Wallaby attacking momentum in the top of the table deciding Pool A match in Melbourne on Sunday.
The winner goes to the top of Pool A and quarter final 2 against either Scotland or Fiji, considered the easier of the two possible knockout games in this section, the loser plays France in quarter final 3.
The Irish have been meticulous in their planning, preparing for whatever tactics the Wallabies might employ.
Scrum doctor
Australian born Ireland scrum doctor Tony D'Arcy says the game could very well be decided at the scrum and in the tackle because both teams have very good backs that more or less cancel each other out.
D'Arcy says Ireland are ready for any wheeling tactics Australia might employ at scrum time, suggesting the Wallabies “step away” on the tighthead side, a legal manoeuvre causing the scrum to rotate anticlockwise.
It is a tactic that opens up the right hand side of the field for the attacking team, pushing their backrow at the opponents try line and simultaneously forcing the defending backrow away from the ball.
Australia used the tactic to great effect against the bigger Argentine pack in the 24-8 win in game one at Telstra Dome, winning at least two penalties for collapsed scrums when the Pumas chased the wheel and lost their footing.
“The scrummage is very important for both teams,” D'Arcy said. “Australia definitely fades on the tighthead side and I am sure Australia will have some little bits and pieces in the scrum.
"Ewen McKenzie (Australian forwards coach) is a very smart guy. Both teams scrummaging will be very important because both teams have very good sets of backs.”
Size matters
Size also matters to the Irish as they prepare to attack Australia at what is called the tackle zone, convinced the way to beat the defending champion is to slow down the ball George Gregan has to distribute to brutish ball runners like Nathan Sharpe and David Lyons.
“Our job is to not let them get going,” D'Arcy said. “When you look at the data we only have the Argentine game as a guide at RWC because the other two games were confusing from an analysis point of view.
"The challenge for us is to stop them at the tackle zone. They are very talented in the forwards and have a number of very good ball runners.”
A win would give Australia a share of the Rugby World Cup record of 10 successive wins held by New Zealand and South Africa.
Ireland have won eight on the trot and 18 of the past 20, their only losses, 42-6 to England in the Six Nations at Landsdowne Road in March and a 45-16 result to Australia at Subiaco Oval in June.
Friendly rivalry
The rivalry between the two teams is intense, remaining largely friendly over 22 meetings.
Australia holds a 15-7 record in the head to head, with three of those matches played at RWC, the last a 22-3 win to Australia, the most memorable the last minute 19-18 win by Australia in the 1991 quarter final.
The nations have swapped standings on the world rankings twice during the Tournament, Ireland currently occupying third and Australia fourth.
D'Arcy, a former Wallaby tight head, is responsible for the Irish scrum and is highly qualified to pass the rule over the Wallaby forward pack.
The man who coached Brisbane club GPS to its first Premiership in 30 years in 1996, can’t believe the level of criticism directed at the Wallabies in the Eddie Jones era.
“We are under no illusions that Australia has one of the premier packs in world rugby,” D'Arcy said.
“You don’t see the Wallabies losing too many lineout balls. They are pretty good at the set piece. Their scrum isn’t often disrupted."
Making progress
D'Arcy said the Irish scrum is progressing very well under his tutelage.
“Australia is the real test,” D'Arcy said. “In the area I am qualified to talk about which is the scrum I am happy with the progress we have made.
"We are now at the platform that we have been preparing to compete on.”
The often maligned Australian front row has come in for particular scrutiny as the Irish search for any advantage.
“Ben Darwin is very good and must have come back up to push Al Baxter out from what looked like the starting XV,” D'Arcy said.
“I coached Brendan Cannon at Brothers in Brisbane and he a fierce competitor who will be going at the same speed in minute 79 as he was in minute 1.
"Not to forget Bill Young who might not be the biggest but is certainly one of the best tight heads in the world.”
Plan B
The Irish have prepared a Plan B in case the frontal assault does not work, but D'Arcy was not prepared to reveal its contents.
“We know that we have to beat them at whatever structure they bring to this game," he said.
"Whether they attack down a narrow channel or go to a wider channel which they are also capable of we have to play what we can see in front of us.”
“Australia have got some pretty good players and a pretty sound structure, they always know where they are going three phases ahead.”