Argentina, who looked far from their usual high standards against England, went on to beat Samoa, Chile and Japan and entered Saturday's quarter-final against Wales riding a long-built momentum.
Wales had sailed through the pool phase and did not seem ready to play knockout rugby. Argentina were.
"I don't think there has been some radical turnaround. I think we have built from what we have learned, try to be a bit better at it the next game," coach Michael Cheika said after his team beat Wales 29-17 despite falling to an early 10-0 deficit.
"We knew the first game would be a bit rough from us. We learned a lot because there was a lot of first-time World Cuppers in there. I think they learned a lot from that game in terms of handling what is knockout footy in what wasn't knockout footy - every game since has been knockout."
Argentina have been looking at the World Cup as a whole.
"All that work you put in as a foundation is what you bank on in this tournament," Cheika explained.
"You have got to look at it with your playing roster, the team you are going to play, what the turnaround time is and just try and plan it out so it works to get a bit of flow."
The next step, however, might prove a bit too high for Argentina as they face three-time champions New Zealand for a place in the final on Friday, but the Pumas should not be written off.
They beat the All Blacks, who will need to recover from a bruising quarter-final against Ireland, in the Championship last year in Christchurch and will not go down without a fight.
"What we need is clear, that we are going to be able to prepare, how we are going to prepare and how we are going to phase the obstacles - a good simple strategy so that we can be ready for battle and the physical war next weekend," said Cheika, who pointed out that Argentina were not being dealt the same hand as their opponents.
"In 2015 (when Argentina reached the semi-finals in London)we were playing in the same stadium. It was easy to prepare, the recovery was good," Cheika said.
"In 2023, we have been told, I don't know why, we cannot go there before Monday. We are not going to do anything tomorrow (Sunday). We are going to travel on Monday so we are going to lose one day of preparation.
"The other team will obviously already be in Paris waiting for their semi-final. This will have to change. I cannot implement the normal preparation phase in this short amount of time I have been given."
