"These players are such good people, without getting too emotional," said beaming former Wallabies coach Cheika after the clash at the Stade de Marseille where Argentina became the first side into the semi-finals
"They have worked really hard and that hard work showed at the end of the game today.
"They wanted to fight for it, they wanted to earn it. We were behind so it takes a bit of leg work.
"The whole 23, along with the 10 who didn't play, put in a huge effort."
For captain Julian Montoya success was the culmination of a long road walked together.
"It comes from our personality and the way that we train," he said.
"We trust each other. We are a very tight group. I know you just see the 15 on the pitch, or the 23, but there is a group of people behind us who are unbelievable.
"They work day and night. We are the fortunate guys who wear the jersey but this is a team effort.
"We know it is not going to be perfect; life is not perfect. It's how you embrace the moment and fight for each other. That's what rugby is about."
Argentina will play the winner of Saturday's other quarter-final, between Ireland and New Zealand.
"Two more weeks with this team. I don't want this to end ever," Montoya said.
"We need to be better, to be clinical in a lot of things. I know I can be more demanding but I am very proud of this team."
Sydneysider Cheika, who coached the Wallabies between 2014 and 2019, said he was not looking too far ahead just yet.
"I don't know if we'll go with the sweeping statements just yet. We will wait and see," he said of Argentina's World Cup journey.
"We are just thrilled to be going to Paris, we haven't had a taste of it yet at this World Cup.
"I know we won't be favourites in the semis but we'll be giving it our best."
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