Martinez had Belgium come out in a different look in the quarter-final against the Selecao, abandoning the set-up that had netted four wins in four matches for the Red Devils.
The move paid dividends for Belgium as Kevin de Bruyne, moved further up the field in the day’s formation, unleashed a rocket from the edge of the area to score his side’s second of the night after the Red Devils had gone up thanks to an own goal.
It is what ultimately proved the winner after Renato Augusto had drawn Brazil one back in the second half.
Marouane Fellaini and Nacer Chadli, who were impact subtitutes in the comeback win over Japan, were handed starts to provide more defensive cover, with Dries Mertens and Yannick Carrasco making way.
Belgium also looked particularly deadly on the counter, as the set up allowed them to attack the space vacated when Marcelo got forward for Brazil.
And Martinez was full of praise for his side after the upset victory, noting their resilience and determination not to let Brazil impose their will on the game, resulting in a "special" win.
“They did it. You saw incredible heart from this team,” Martinez said post-match. “You have to accept that Brazil have finesse and they will break you down but we did not accept it.
“This is something special. These boys deserve to be real special people back in Belgium.”
Martinez talked about the tactical changes he made, claiming he has never lost a game in the set up, but noting it required perfect execution in a relatively short period of time.
"I never lost a game on the tactics board, it's the execution that matters and the execution was magnificent,” Martinez added. “Players have to be brave to change the way we play and we had two days to do it. That is down to desire, they wanted to make it happen.”
The victory sees Belgium into the World Cup semi-finals, something the nation has not done since losing to Argentina in 1986.
But while the famous win against Brazil to achieve that will not be soon forgotten, Martinez wants to make certain his side is ready to go when they face neighbors France on Tuesday.
"It is special. We can't let them down back home now,” he said. “We have beaten Brazil in the World Cup, we have created a nice memory, let's treasure it and pass it down.
“Now we need more energy for the semi-final."