Meanwhile, the Saru Academy Sevens outfit, playing as the Samurai Internationals, successfully defended their Dubai International title after beating Spain 22-14 in the final.
Reigning HSBC World Rugby Sevens Series champions Fiji were crowned Dubai Sevens champions following their 28-17 win over England in the Cup final.
Cape Town will host the next tournament on 12 and 13 December.
In their first match of the day, the USA followed up their historic win over New Zealand on Friday with a dramatic 21-19 quarterfinal success over South Africa to eliminate the defending champions from the Cup competition.
Parry Baker scored first for the US and he was followed by Justin Geduld, who had a good tournament for SA.
Philip Snyman and Seabelo Senatla also scored to stretch the SA lead to 19-7.
But two converted tries by the USA and the yellow card of Senatla meant the Blitzboks had to fight back for one more score, however, the USA held firm.
The Blitzboks then defeated Argentina 26-5 in the Plate semi-final. Cheslin Kolbe (2) and Hougaard scored the tries to give SA a 19-0 halftime lead.
After the restart, Geduld added another try before Juan de Jong was yellow carded for a high tackle. Australia started the Plate final the stronger side and led 14-0 at halftime thanks to tries through Sam Meyers and Ed Jenkins.
Kwagga Smith was sent on after halftime as one of several changes and his ball poaching skills and positioning allowed him to score two converted tries to level the scores.
With the scores locked at 14-all after normal playing time, Hougaard raced clear to dive over in the corner for the winning score in extra-time, after splendid work by Geduld.
It was not the result South Africa wanted, but the Plate success mean they will arrive home with some momentum for next weekend's inaugural HSBC Cape Town Sevens tournament.
Blitzbok skipper Kyle Brown praised his team for fighting back after their setback against the USA.
“The guys showed good fighting spirit and character to eventually win the Plate. We missed Werner and Cecil because of injury, but others such as Justin, Francois and Cheslin stepped up to help us finish the tournament with a win,” explains Brown.
According to Neil Powell, the Springbok Sevens coach, Cecil Afrika and Werner Kok will undergo injury assessments in Cape Town. “Werner injured his knee in the quarterfinal and Cecil felt a hamstring strain on day one, so we didn't wanted to risk him and that's why he played no further part in the tournament,” explains Powell.
He added: “Both players will undergo scans back home in Cape Town and they will be given as much time as possible to recover to come into consideration for selection for our home tournament.”
The Springbok Sevens arrive at 16h25 on Sunday at the Cape Town International airport, while the Academy squad will land earlier at 11h30.
The top of the World Series standings following the Dubai Sevens: 1. Fiji 22 points 2. England 19 3. United States 17 4. New Zealand 15 5. South Africa 13 - African News Agency (ANA)
Original source: Blitzbokke win Dubai Plate final