England, Scotland and Wales were all beaten in the Cup quarter-finals as South Africa won the Dubai Sevens - the second leg of the Sevens World Series.
England were defeated 29-7 by New Zealand, while Australia beat Scotland 22-17 and Fiji saw off Wales 31-17.
The home nations went into the Plate semi-finals with Scotland beating Wales 31-7 before losing the final 26-12 to Argentina, who had defeated England.
South Africa beat Australia 33-7 in the final to win the tournament.
The Springboks had earlier beaten Argentina 40-0 in their quarter-final and followed that with a 28-0 victory over New Zealand in the last four.
Fiji, who won the first leg in Australia, beat New Zealand 26-12 in the play-off for third place and lead the overall standings on 39 points, two ahead of South Africa.
The third leg of nine in the series takes place in South Africa next week.