Springbok coach Heyneke Meyer lamented his team's mental shortcomings after Saturday's loss to Australia in Perth.
South Africa squandered a 10-point lead to lose 26-19 as they failed to bounce back from their shock draw with Argentina.
Meyer said the result could be traced to a combination of a couple of simple mistakes and some missed opportunities, adding that the yellow card issued to prop Tendai Mtawarira just before half-time was a pivotal moment in the match.
"It is all about handling pressure, being mentally tough and showing character," said the Boks boss.
"Test match rugby is not always about who plays the best, it is about who handles the pressure the best.
"To win away from home you have to have a great game-plan and execute it. I thought we executed the game-plan well for the first 60 minutes. I thought we put them under pressure but we had two soft moments in the game that cost us and away from home you can't make those mistakes.
"There was a little bit of a lack of experience on the field
"But all credit to the Wallabies. They came back when it mattered.
"There was a huge improvement but I'm still not happy with our performance. We need to play better," he added.