Brazil coach Luiz Felipe Scolari said he and his team "can't be polite anymore" after squeaking past Chile on penalties in their round of 16 match on Saturday.
The hosts are the overwhelming favourites to win the World Cup but faced a scare after finishing 120 minutes even at 1-1 with their South American rivals.
Scolari said a change of mentality is needed as the Selecao head to the quarterfinals.
"It's about time for us to defend ourselves and go back to our own style," Scolari said. "I'm a little oppressive at times. We've been quite polite and I can't be polite anymore.
"We took it upon ourselves, this mission, that we must be champions. We passed it on to the players and the people embraced the idea. Now the people are demanding it from us, but that's because we said we will qualify and win. Now we have to give it back to them.
"If you make a promise, you must deliver. You will go until the end and do whatever possible. That's what the players are doing. This is the fourth step. There are three more, so that we can reach heaven."
Brazil have been providing nightmares for Chile for decades. All four times the Chileans have reached the knockout stages of the World Cup, Brazil have eliminated them. But Scolari was complimentary of his opponents after the match.
"As we had expressed seven or eight months ago when we heard about the draw, there was a potential to face Chile," Scolari said. "They are a very well-organised team and have a good technical plan. It was an intense and balanced-out match that it had to go to a penalty shootout."
Brazil will take the rest of Saturday and all of Sunday off, according to Scolari, as they prepare to face Colombia on Wednesday.
"In every match, difficulties are escalating and we need to improve, Scolari said. "With this level of emotion as it happened today, we can turn it into a positive thing. We try to take the best moments out of a match and value them.
"As some people said, the team is new and even the most experienced players have felt the pressure. The emotions are different. Since we have so many new players, little by little they gain experience. We gain experience as we go on, so let's see if we can make fewer mistakes.
"We have a good national team. We're not worse or better than those who have qualified. We are fighting at home and a lot today was due to the fans. At some times, we were not doing well and still, they were supporting us. That was wonderful and very, very important for us."
With the eyes of the nation on the team and in talisman Neymar in particular, Scolari said his star player is handling the pressure with poise.
"Neymar is 21 or 22 years old, but he is experienced, as if he were 35 years old. He is a mature player," the manager said. "He can deal with the difficulty of not having the experience that comes with age.
"He's very good psychologically. There are details in his life, in his history, that show that he's been ready since he was 17, 18 years of age. He's a simple person and likes playing football. He loves his job and loves what he does."