Australia's men have produced their worst performance of the Sydney Sevens, crashing 24-10 to Samoa to finish the event joint-seventh.
A host of errors and a lack of focus proved costly for Australia, who had won all three of their pool games at Allianz Stadium before losing 17-14 to France in Saturday's quarter-final.
Samoa scored four tries to two in the fifth-place semi-final, but finished the game with just five players.
Neueli Leitufia was sent off in the dying minutes for a tap tackle on Stuart Dunbar, who received a yellow card for retaliating with an elbow.
Vaa Apelu Maliko was given a yellow card right at the end, with Henry Paterson scoring a late consolation try for the home side.
Maliko started the home team's woes when he pounced on a loose ball to score an easy try in the second minute and Taunuu Niulevaea crossed twice before halftime to leave Australia trailing 17-0.
It got even worse two minutes after the break, when Faafoi Falaniko scored Samoa's fourth try.
Down 24-0, Australia finally responded through a Darby Lancaster five-pointer, but the damage had been done.
"We can come up with a lot of excuses, at the end of the day we didn't turn up in pressure moments in that last game," Australia's assistant coach James Stannard said.
"We pride ourselves on being consistent in our performances and we were far from that this weekend.
"We had some moments during the (first) two days, but (we were) not good enough."
Stannard denied the side lacked leadership after captain Henry Hutchison suffered a knee injury in the final pool game.
He said the experience of dealing with adversity for young players like Lancaster and Dally Bird was one of the positives Australia could take from the tournament.
"Our defence up until that last game had been pretty good all tournament," Stannard said.
"We worked well together. We stuck to our systems a lot and we played off the back of our defence and scored a lot of tries.
"Just unfortunately that last game we didn't turn up in the proper mind space to deserve to win."
Earlier, Australia's women rebounded from Saturday's shock loss to France to beat Great Britain 19-0 and remain in the hunt for a top-five finish.
The host nation scored three tries to nil, with Bienne Terita crossing after only 18 seconds of Sunday's match at Allianz Stadium.
Australia will finish either fifth or sixth depending the outcome of their last match against Fiji, who beat Japan 40-7 on Sunday morning.
