A comedy of errors in a horror second half have put Australia’s men’s sevens Sydney title defence in early disarray at Spotless Stadium.

The hosts lost to Argentina 29-14 in the first of three pool games to be played on Saturday, leaving them needing wins against powerhouse South Africa and Tonga later in the day to have any chance of defending their title.

Tim Walsh’s men went to the break ahead 7-5 thanks to a late Simon Kennewell try, but unforced errors starved them of possession in the second stanza as the South Americans ran away with it.

First the visitors ran 70m almost untouched from the restart to jump ahead, before regathering their own restart to score from the next play against a flat-looking Australia.

Australia finally earnt some possession five minutes into the second half but immediately coughed it up, with several bumbling efforts allowing Rodrigo Etchart to plant a hand on the loose ball in-goal for a 29-7 lead.

Maurice Longbottom’s late try at least reduced the margin in a horror start to the side’s only chance to impress on home soil this year.

Australia’s women’s outfit will hope for a sharper effort in their quarter-final against France at 1.56pm (AEDT), before the men return against Tonga (3.56pm) and South Africa (8.23pm).

Sitting fourth overall, Australia’s women have a golden chance to log big points after landing on the opposite side of the draw to New Zealand.

A Sunday semi-final against Ireland or Spain awaits the winner of their quarter-final but after a day of upsets on Friday highlighted by England’s exit Manenti isn’t getting ahead of himself.

“Ireland have knocked off teams, Canada’s been beaten, USA’s been beaten,” he said.

“There’s lots of teams that can win and whoever plays well at the right time is going to sneak through.”

Saturday Schedule:

10.28am v Argentina (men)

1.56pm v France (women’s quarter-final)

3.56pm v Tonga (men)

8.23pm v South Africa (men)