Australia boss Michael Cheika may be the new boy among the major rugby players but he has proved that he learns fast.

The Wallabies have won the southern nations' Rugby Championship and reached the World Cup semi-finals in less than a year.

Fly-half Bernard Foley's last-minute penalty saw Australia to a 35-34 win over Scotland and a World Cup last four place at Twickenham on Sunday after a major scare for the two-time world champions.

Cheika's men now face Argentina in next weekend, with defending champions New Zealand taking on South Africa in the other last four clash at Twickenham.

With no Northern Hemisphere team in the last four for the first time in Rugby World Cup history, the tournament now becomes a repeat of the Rugby Championship, which was shortened this year to make room in the calendar for the World Cup.    

"It does mean everyone knows each other very well," said Cheika, thrust into the job of Australia coach last year after the resignation of former boss Ewen McKenzie.

"I am the junior member of the Rugby Championship, the other coaches, Daniel Hourcade (Argentina), Steve Hansen (New Zealand) and Heyneke Meyer (South Africa) have all got more experience than me.

"But we will prepare as best we can and put a performance together on Sunday."

Australia pulled off one of rugby's great escapes Sunday, although they outscored Scotland five tries to three.

Things were looking bleak for the Wallabies at a rainswept Twickenham when, with barely six minutes left, Scotland centre Mark Bennett's intercept try under the posts and the ensuing conversion left the Wallabies 34-32 behind.

- 'Running footy' -

"Usually if you kick a goal at the end of the game to win, it's a pretty good escape," said Cheika. "Saying that, if you score five tries, then you expect to be near the winning side.

"Maybe we shouldn't have opened it up for them but we wanted to play to our identity which is to play running footy," he added.

"When the goal (conversion) went over for Scotland, many teams would have thought 'let's go home, we have had a good run'. I just liked the way we got back into the game any way we could."

Australia prop Sekope Kepu told AFP: "It's funny, it's just dawned on me that it's now a Rugby Championship affair. But it's irrelevant what we did in the Rugby Championship, this is a whole new beast. We're very excited."

Wallaby wing Adam Ashley-Cooper, a try-scorer against Scotland, warned an improved performance was needed to tame the Pumas next weekend.

"Each game presents you with areas you need to address," he said. "We need to tidy up our exits, get out of our half a lot better.

"I think the most important thing is to know that we're in a semi-final and be happy about that. They don't come around often."

The Wallabies beat the Pumas 34-9 in Mendoza in July.

But Argentina served notice of their World Cup quality with a convincing 40-23 quarter-final win over Six Nations champions Ireland in Cardiff on Sunday.

"They've improved a lot," said the 31-year-old Ashley-Cooper of Argentina. "They have the ability to tackle all over the field now.

"We know they've got a dominant forward pack. They've got great set-piece and now they've got outstanding backs," added Ashley-Cooper, a veteran of 112 Tests.

"They're a threat from one to 15 so we're going to have to look very closely at their game and formulate a strategy that we think will beat theirs."
Source: AFP