Wales v Australia
Stephen Larkham is a veteran of 102 Tests for Australia
Millennium Stadium, Cardiff
Saturday, 15 September
Kick-off: 1400 BST
Live coverage on BBC Radio 5live & the BBC Sport website
Wales defence coach Rowland Phillips says targeting Stephen Larkham is the key to stopping Australia's potent backline at source on Saturday.
Many have tried in the 33-year-old fly-half's career, but that is what Wales must do to beat the Wallabies in their World Cup pool clash in Cardiff.
"Larkham is a threat, he just seems to get better with age," said Phillips.
Australia wing Adam Ashley-Cooper is in danger of missing the clash with Wales because of a painful toe injury.
Ashley-Cooper damaged the ligaments in his toe shortly after scoring a try in Australia's 91-3 thumping of Japan in Lyon on Saturday.
The injury is reported to be responding well to treatment, but if Ashley-Cooper does not recover in time his most likely replacement is Drew Mitchell.
Whatever happens in the wide positions, Larkham will almost certainly start in the number 10 shirt at the Millennium Stadium to win his 103rd cap.
The match is widely regarded as the make-or-break clash to decide who will top Pool B at the World Cup.
His class was evident to see last weekend in Australia's hammering of Japan in their opening game of the World Cup.
Wales, meanwhile, were given a scare by Canada, trailing at half-time before putting together an emphatic second-half recovery to win 42-17 in Nantes.
But Phillips knows that Wales cannot afford to give the Wallabies any such head-start if they are to win this crunch match.
"Larkham's decision making is always spot-on, I'm sure closing him down will be key to any success against Australia," Phillips added.
"He's not only a danger by himself, but he brings the best out of the guys around him.
"However, there is always a danger of focussing too much on one person.
"What marks this Australia team is the quality of players across the park and that offers a real challenge to teams when they are preparing their defensive strategies.
"But we don't fear Australia, we are excited by the challenge.
"They will respect us and know that we were very unlucky not to beat them in Sydney in May."
We don't fear Australia, we are excited by the challenge
Wales defence coach Rowland Phillips
Australia needed Stephen Hoiles' last-gasp try to deny an under-strength Wales a first win over the Wallabies in Australia since 1969.
The second Test of that mini-tour a week later saw Australia finish comfortable 31-0 winners.
But the previous November the two sides drew 29-29 at the Millennium Stadium in Cardiff, while in 2005 at the same venue Wales claimed a first win over Australia since 1987.
And it is at the Millennium Stadium that the two sides clash again on Saturday, with Wales hoping that home advantage will aid them after the opening pool matches in France.
"We would be happy to stay here but there's the bonus of familiarity back home," Phillips said.
"I don't think it will bring an added pressure by playing in Cardiff. Obviously there is an advantage of playing at home.
"It is certainly a chance to spend some time with our families. It's a long tournament and sometimes the time you spend away from each other as a squad is just as important as the time together."
Wales head coach Gareth Jenkins will announce his team on Thursday when they return to their usual headquarters at the Vale of Glamorgan Hotel, just outside Cardiff.