Carlo Ancelotti kept his trademark cool to guide Brazil into the World Cup last 16, but defender Gabriel admits there is room for improvement as they attempt to defy the sceptics.
Brazil were a half away from going out of the tournament before fighting back for a dramatic 2-1 win over Japan in Houston.
Down 1-0 at halftime after a wonderful solo goal by Kaishu Sano, Casemiro silenced his doubters to level for Brazil and their legion of fans with a 56th-minute header.
Ancelotti sent on Gabriel Martinelli on 66 minutes, and with extra time looming, the Arsenal winger struck in the fifth minute of added time to leave Japan's players in tears.
A side attempting to win Brazil's sixth World Cup – and first since 2002 – face Norway or the Ivory Coast next.
Arsenal centre-back Gabriel, whose cross was converted by Casemiro, said: "We faced a great team, we ended up conceding a goal but we knew we had the possibility of coming back into the game.
"So it was about showing a bit of composure in the final third."
That was the message to the players from the famously laid-back Ancelotti at halftime – remain calm, keep plugging away, the goals would come.
After an even first half against a Japan team considered dark horses by some, Brazil dominated in the second period.
"At halftime I told them not to lose patience because we were going to score sooner or later," said Ancelotti.
Brazilian media outlet O Globo praised the Italian, Brazil's first foreign coach since 1965, for his tactical flexibility.
"Ancelotti has stated several times that he doesn't want the national team to have just one identity, but rather, several," said O Globo, adding that the "chameleon" style could be Brazil's "trump card".
"Brazil's greatest weapon was Ancelotti's reading of the game," it said.
ANCELOTTI UNWAVERING ON CASEMIRO
This Brazil side has been panned at home as being only a shadow of the great sides of yesteryear after labouring through qualifying.
They boast the Real Madrid attacker Vinicius Junior, who scored four times in the group stage, but are otherwise not laden with world-class talent.
They were unimpressive in drawing 1-1 with a strong Morocco team to start the group phase, before 3-0 wins over limited Haiti and Scotland teams.
And while Japan are a technically talented side with big ambitions, they came into the last-32 encounter having drawn two and won one – a 4-0 thrashing of Tunisia – in the group phase.
After conceding, the defender Danilo having given the ball away, Brazil's thousands of fans grew restless in Houston.
The 34-year-old midfielder Casemiro has been a particular focus of their discontent.
But with Ancelotti – at his first World Cup as a coach but a serial winner at club level – holding the reins Brazil turned it around for an ultimately deserved win.
They would be favourites to beat Norway or the Ivory Coast, and suddenly the quarterfinals are in view.
Gabriel, one of the outstanding defenders in the Premier League in recent years, struck a note of caution.
"Let's rest now and think, we know this competition isn't easy and they are two great teams," he said of their next opponents.
"We need to improve for sure."
Brazilian media flagged other concerns.
There was the sight of attacking midfielder Lucas Paqueta going off in distress and replaced at halftime.
Barcelona winger Raphinha has been injured since coming off against Haiti.
And for some pundits, Casemiro, despite his goal, and the 34-year-old fullback Danilo are liabilities.
Ancelotti will hear nothing against defensive midfielder Casemiro, having brought him back into the fold after becoming coach in May last year.
"Casemiro is a leader," the 67-year-old said.
"He knows his position very well, how to play his position.
"No one is teaching him how he has to play in his role. That’s very important."