Gregan believes Australia must improve

The Wallabies now face Scotland after winning 17-16 in Melbourne, while the Irish face a tougher quarter-final obstacle in France.

And Gregan said: "We're happy to have got through that.

"Obviously we didn't play the way we wanted to but that was a lot to do with the way the Irish performed."

Australia had initially looked on course to dominate the match as George Smith scored early on.

Match report: Australia 17-16 Ireland

And the trusted boot of Elton Flatley moved them 14-6 ahead shortly after the re-start.

But Ireland produced a thrilling fightback as Brian O'Driscoll slid into the corner to score.

Flatley added another penalty, before O'Driscoll's 67th-minute drop goal set up a tense finale, which the Australians just edged.

Gregan said: "They put us under a lot of pressure and had most of the field position in the whole game."

And looking ahead to next weekend's tie against Scotland, he added: "There's lots of areas to improve but we hung in their and won a tight match which is always a good thing to do."