Old fashioned ticker has propelled Australia's new age rugby sevens outfit into the quarter-finals of the Adelaide tournament.

For the second time in consecutive days, the callow Australians mowed down fancied rivals to post stunning upsets at the International Rugby Sevens tournament at Adelaide Oval.

The Australians on Saturday eclipsed highly-rated Samoa 26-19 courtesy of a Richard Kingi try in the final 10 seconds.

Australian coach Michael O'Connor was delighted with the gutsy triumph, which came after the hosts failed to touch the ball for the initial four minutes of the match - and lagged 12 points behind with 5m40s remaining.

The pool match victory followed Australia's last-minute heroics against England on Friday night which reaped a shock 21-17 win.

Those results were enough to progress Australia into Sunday's quarter-finals but the hosts then pounded Portugal 31-5 in their last preliminary fixture for good measure.

"I am just delighted for the boys because they have shown they can finish off and close out a game," O'Connor said.

"They showed a lot of ticker."

Australia started last November with just two players with international sevens experience, and entering the Adelaide tournament were placed ninth with just 14 points - some 70 behind overall leaders South Africa.

"Their fitness has come a long way - we started well behind the pack and it is such a big component in Sevens, the fitness, and we are up there now," O'Connor said.

"The unknown area has been what's between the ears, the grey matter, and experience and they are starting to understand Sevens now.

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