Craig Joubert penalty call not decisive - George Gregan

Former Australia scrum-half George Gregan does not believe Craig Joubert's controversial decision to give the Wallabies a late penalty decided the Rugby World Cup quarter-final with Scotland.

Australia were trailing 34-32 at Twickenham on Sunday after Mark Bennett's breakaway try seven minutes from time gave Scotland the lead.

However, Joubert provided the Wallabies with a late lifeline by awarding Michael Cheika's men a penalty for offside, although the ball appeared to have come off the hand of an Australia player.

Bernard Foley made no mistake in converting the penalty to give Australia a 35-34 win and a place in the semi-finals against Argentina.

Upon the conclusion of the match Joubert ran from the field, with former Scotland star Gavin Hastings describing his actions as "the worst thing I have seen on a rugby field" and calling for the South African official to never referee an international again.

But asked about the decision by Omnisport, 1999 World Cup-winner Gregan said: "Yeah it was a contentious decision."

"But, look it's funny, it sounds like I'm being biased but I'm pretty impartial, and I don't have too much emotion when it comes to watching games in the sense that I can look at it.

"I think there was a really big decision during the 48th or 50th minute when Will Genia was deemed to have knocked it on. When Adam Ashley-Cooper scores in the corner. I didn't see the knock-on.

"The Wallabies score there and they kick the goal it becomes a 29-19 match, with 30 minutes to go. The game changes.

"So you have those moments in Test matches. I think what defines good teams is their ability to take those moments.

"What defines an epic Test match is something such as that. Did it hinge on that decision? I personally don't think it did because I think you can always look back at those last minute decisions.

"A team, if you win or lose, you had a chance to win that game earlier."

The Wallabies will face the Pumas in the semi-finals at Twickenham on Sunday.