These results leave South Africa in second place on the log and they are in a battle of pool survival on Saturday, when they face New Zealand, who earlier defeated Uruguay and Australia.
Quewin Nortje was the star against Uruguay in the opening match, but the debut try of Gino Cupido will also live long in the memory banks of all.
Nortje found space on the outside before offloading to Siviwe Soyizwapi to open the scoring in the second minute and then scored himself soon after, following a blistering run down the line.
The Blitzboks defended really well in the opening half and from such stout defence, Shilton van Wyk benefitted from a loose pass and raced 80 meters to score for a 19-0 lead at the break.
The second stanza had more of the same coming to the South American side.
Nortje again blitzed them on the outside for his second before Cupido scored on debut and with his first touch of the ball. The lanky outside centre ghosted past his marker to ran in from 70 meters out.
Uruguay did get one back after a rare, missed tackle by the South Africans, who retaliated immediately with a try by Ricardo Duarttee, who stepped inside some defenders for his first points of the tournament.
The match against Australia showed little of that momentum laid down in the first encounter. Australia conceded a yellow card in the opening minute, but the Blitzboks could not make the extra number work and once the Aussies were numbered up again, they pounced.
The Aussies scored in quick succession, both times when the SA defensive alignment got in wrong, while their third try came from a kick-off receive that the men in green got horribly wrong.
Selvyn Davids pulled one back for his side, but when Australia scored again, the defeat was a stark reality for South Africa.
They play New Zealand at 07:34 on Saturday morning.
Scoring summary:
South Africa 40 (19), Uruguay 7 (0)
SA - Tries: Siviwe Soyizwapi, Quewin Nortje (2), Shilton van Wyk, Gino Cupido, Ricardo Duarttee.
Uruguay - Try: Alfonso Silva. Conversion: Juan Manuel Tafernaberry (14')
Tristan Leyds (2), Selvyn Davids, Ricardo Duarttee (2).
South Africa 7 (0), Australia 26 (21)
SA Try: Selvyn Davids. Conversion: Ricardo Duarttee.
Aus Tries: Josh Turner, Henry Paterson (3). Conversions: Maurice Longbottom (3).