Argentina defeated the Blitzboks 7-5 in a fifth-place playoff that was full of suspense right to the end. There were no score at halftime, with the rain making handling difficult for the players.
Earlier on Sunday, the Blitzboks were beaten 10-7 by Fiji in the Cup quarter-finals before they smashed the USA by 38-7 to book their place in the playoff against Los Pumas.
The first half against Argentina was a real arm wrestle, with neither side able to put points on the board. The Blitzboks tested the Argentine defence with long, driving kicks up-field, but the South Americans held firm.
Argentina in turn tested the South Africans with several onslaughts, but the Blitzboks showed steel in defence to keep their opponents away from their line.
The game finally came alight right at the end with both sides going over. Jacquin Pellandini breached the SA line after the Argentineans had managed to hit several gaps in the danger zone, and he converted his own try to hand his team a 7-0 lead with less than two minutes left.
However, Ricardo Duarttee then delighted the fans when he produced a brilliant sidestep to score in the corner. The conversion was wide and in real soccer style, Argentina headed the ball into touch from the restart to claim the 7-5 win.
In the first game on Sunday, Fiji just managed to beat the Blitzboks by 10-7 in a tense Cup quarter-final. Playing without the experienced Zain Davids due to a broken hand, South Africa came close and left the field with their heads held high as they could have won the game having led by 7-5 at the break, but in the end Fiji held on for a close win.
Shaun Williams broke the deadlock in the fourth minute after some good attacking play, with Duarttee making it 7-0 to South Africa with the conversion.
Fiji hit back through a long-distance try by Iowane Teba after a defensive lapse by the Blitzboks, but the conversion sailed wide and the South Africans led by two points after a tight first half.
The second half delivered more of the same until Napolioni Bolaca scored Fiji's second after they found some space on the right.
The Blitzboks then threw everything they had into the encounter and were hot on the attack in the Fijian 22 when the referee ruled obstruction, after which the experienced islanders simply ran the clock down to book their spot in the semi-finals.
In the fifth-place semi-final against the USA, South Africa started very well with Christie Grobbelaar going over in the first minunte following a great run by Duarttee, who was stopped just short of the try-line.
The USA hit straight back though, Lucas Lacamp scoring from the restart after two missed tackles which allowed their opponents to finish 60m upfield under the uprights.
Grobbelaar then put South Africa in the lead after Sebastiaan Jobb took a quick tap penalty and put the big forward over for his brace, with Ricardo Duarttee's conversion making it 12-7.
The USA didn't give up and almost scored, but superb defence by Shaun Williams saved a certain try, which underlined the determination in this Blitzbok team.
They cut loose in the second half to seal a great win, with Tiaan Pretorius scoring 30s after the restart to show the Blitzboks' intent.
Then the three new players in the squad - Ethan James, Donovan Don and Jobb - got their names on the score sheet in a memorable match.
James scored from a brilliant kick into space by Duarttee; Don ran 80m after scooping up a loose ball on the SA 22; and Jobb went over after the hooter. All three were converted to make it a big win for the Blitzboks.
Springbok Sevens 7 (7) Fiji 10 (5)
Springbok Sevens - Try: Shaun Williams. Conversion: Ricardo Duarttee.
Fiji - Tries: Iowane Teba, Napolioni Bolaca.
Springbok Sevens 38 (12) USA 7 (7)
Springbok Sevens - Tries: Christie Grobbelaar (2), Tiaan Pretorius, Ethan James, Donovan Don, Sebastiaan Jobb. Conversions: Ricardo Duarttee (4).
USA - Try: Lucas Lacamp. Conversion: Steve Tomasin.
Springbok Sevens 5 (0) Argentina 7 (0)
Springbok Sevens - Try: Ricardo Duarttee.
Argentina - Try: Joaquin Pellandini. Conversion: Pellandini.