Bryan Habana has admitted that South Africa's shock defeat to Argentina was as bad as anything he has experienced during his career.

The Springboks finished their Rugby Championship campaign on Saturday with a surprise 25-37 loss in Durban.

It was the first time that Argentina had beaten South Africa, who have now lost their last four games.

"The Pumas, to their credit, played positively, and we were caught asleep at crucial moment, and that can only come down to individual concentration and commitment, and that is why the player have to ask themselves if they were truly in the right frame of mind for this game," Habana told Supersport.

"I know the coach and his staff have given us everything we need to perform at our best and we have let them and all South Africans down.

"This is as low as anything I have experienced in my career. Nothing went right, there was no response, a complete lack of energy. As individuals and South Africans, we let the country down not much because we lost, but because of the way we played."

Australia were crowned Rugby Championship winners thanks to a 27-19 triumph over defending champions New Zealand.