The South Americans have been slow burners this tournament, only scraping through the group stages at the end, but have come into their own since the knockout stages begun.
They subjected Russia to their first defeat of 2012 in the quarter-finals and tonight overcame a Japan side who had also had to scrap their way to the last four.
China were their quarter-final victims in a five-set struggle and they still seemed to be feeling the pace tonight as Brazil had too much size and strength for them to handle.
Japan's agility and nimbleness counted for little, with the likes of Sheilla (13 points) and Thaisa (12) utterly dominant at the net.
Thaisa in particular has been an example of how Brazil have fared in the Games. Indifferent at the start, she was faultless against Russia and similarly excellent tonight with four blocks shutting down the dangerous Soari Kimura.
Libero Fabi's defence provided the platform for her team-mates to take the game to Japan and, when the final point was recorded, she was the one the rest of the squad piled on to in celebration.