Mighty Ireland blow the World Cup wide open

Shock in Auckland shows England a final path cleared of Tri-Nations teams

Roar potential: Tom Court celebrates Ireland's victory (EPA)

England went into this morning's game against Georgia knowing a way has been opened to the Rugby World Cup final which will not involve any Tri-Nations teams. Ireland's 15-6 defeat of Australia in Auckland blew the form book apart. England had earmarked the Wallabies as semi-finalists in their half of the draw.

Ireland will believe they can claim that spot. Two penalties apiece by Jonny Sexton and Ronan O'Gara and a drop-goal from Sexton beat the Tri-Nations champions. If Ireland win Pool C by beating Russia and Italy they will meet the runners-up from Pool D – possibly Wales, who faced Samoa in today's early kick-off – in Wellington on 8 October. The winners of that match look set to face England or France in the semi-finals.

The flankers Stephen Ferris and Sean O'Brien were rampant as Ireland inflicted Australia's second-ever World Cup pool defeat. Added to a 22-10 win over the USA it gave the Irish, who lost all four of their warm-up matches, hope of making the last four for the first time.

"It's a performance we knew we had in us," said Brian O'Driscoll, the captain. "We had to dig deeper than we had done in the last five games. [But] it's only half the job done. We have two wins and two more to get."

His Wallaby counterpart, James Horwill, looked suitably aghast at the prospect of a quarter-final against South Africa. He said: "We played some dumb footy. We weren't good enough."