Australia's men have fallen short of a Sydney Sevens final berth, losing 26-12 to top-ranked South Africa in the semi-finals.
The youthful hosts were no match for the championship favourites' speed and power, with the Africans piling on four tries to two at Allianz Stadium on Sunday.
Two second-half yellow cards did not help Australia's cause, with South Africa to meet England in the tournament decider.
The Blitzbokke crossed for the opener within a minute on Sunday, with Kwagga Smith on the end of some superb off-loading.
The home side hit back through a powerful 50m try from young gun Tim Anstee for an unconverted try before South Africa extended their lead to 12-5 on the stroke of halftime with their second try.
Australia had the better run for most of the second half, but the sin-binning of Mick Adams (dangerous tackle) and James Stannard (tripping) in quick succession reduced them to five players.
From there it was all South Africa while Simon Kennewell nabbed Australia a late consolation try.
Australia, ranked eighth in the world, will play New Zealand in the play-off for third.
They have already recorded their best tournament finish of any of the four events in the 2016-17 world series.
Earlier, Australia easily accounted for Wales in the quarter-finals.
