The Springbok Sevens side went down 21-14 to New Zealand in the Plate final in Adelaide.
The South Africans finished top of their group on Saturday, but for the umpteenth time this season they were knocked out of the top phase of the competition. This time they lost 17-14 in the Cup quarter-finals to Argentina.
Relegated to the Plate competition, they scored five tries in out-classing lowly Wales before they met the Kiwis.
The sides were level 14-all at the break, but a yellow card to Frankie Horne before the break proved decisive. Kurt Baker scored the winner for New Zealand early in the second half, and their impressive defence meant they held on for the victory.
In the Cup final, surprise finalists America had their trophy dreams shattered when they went down 38-10 to Samoa.
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