Durban - Argentina coach Daniel Hourcade says his side's first ever victory over South Africa gives him confidence that the team is on track for a successful Rugby World Cup campaign next month.
The Pumas dominated South Africa in all facets of the game to win 37-25 at King's Park, providing a massive boost in confidence ahead of the World Cup in England.
"It gives us self-belief and makes us more confident to continue what we are doing," Hourcade told reporters.
"I'm very happy because we played a perfect game. We were organised, defended well and were effective in attack, which allowed us to score four tries."
Argentina set the tone for their triumph with a try inside the first minute and Hourcade believes the difference in this game was that they were able to take the opportunities that their own fine play and the opposition allowed them.
"We seized the opportunities that were presented and that was a big difference. Previously we have not been able to do that."
Argentina were hugely impressive in the scrum, something captain Agustin Creevy calls a "weapon" for his side, but Hourcade believes his side were on top in every facet of the game.
"We were better in all aspects of the game for the full 80 minutes," the coach said.
"We improved a lot in the scrum from previous matches and in our attack - and that allowed us to beat one of the major powers in world rugby.
"It means we finished the Rugby Championship in the best possible way by achieving an historic result to give us a lot of confidence ahead of the World Cup.
"We played well and we won the mental battle. That is the key to beating the Springboks, you need to be mentally tough."
Argentina will now host South Africa in Buenos Aires on Saturday in a one-off test that serves as a final warm-up for both teams ahead of the World Cup.
The Pumas have been drawn in Pool C at the September 18-October 31 tournament, along with world champions New Zealand, Tonga, Georgia and Namibia.