Isco's hat-trick, together with goals from Diego Costa, Thiago Alcantara and Iago Aspas, sealed a convincing victory at the Wanda Metropolitano, where Nicolas Otamendi netted La Albiceleste's solitary strike.
But Real Madrid defender Ramos, a key member of the squad that won Euro 2008, the 2010 World Cup and Euro 2012, sounded a note of caution.
"We have to be calm because we haven't won anything yet," he said.
"But logically it is the best way to go to the World Cup, with these good feelings.
"For us, these games are not friendlies at all and everyone could see this in every passage of play and in the result.
"We have to keep this ambition but without being arrogant. We have a World Cup coming and we do want to play a very important role."
Argentina were missing star forward Lionel Messi due to a hamstring problem, and Ramos knows Jorge Sampaoli's team suffered without the Barcelona star.
"Everyone in football knows who Messi is," he said.
"He is a unique player in the world and he shows it in every game, not only with Barca but with his national team.
"He was a very important absentee and, obviously, Argentina lost a very important percentage of their potential level.
"But they did not want to suffer the defeat that easily… the second half, due to the result, makes this game be understood differently but in the first half it was very level because Argentina fought a lot."