Not for the first time in this tournament the Beijing 2008 gold medallists had to dig deep to make it through as they knocked Russia out 3-2 at the quarter-final stage. The two rivals battled it out over five amazing sets, with the South Americans the ones to hold their nerve.
It was some achievement to do so too, with Russia, previously unbeaten in 2012, failing to take six match points in the face of some incredible fifth-set defence from Brazil.
In libero Fabiana they had an edge and, thanks to the great work of her and her defensive colleagues, they were eventually able to progress.
Such was the drama that coach Roberto Guimaraes had to compose himself when he spoke to the media after the game.
'I don't know if my heart can cope with much more, oh my God,' he said.
'This game was a bit close and difficult, but my players knew what to do.'
The South Americans will now face Japan, who held their nerve in a five-set thriller with China to book their place in a sixth Olympic Games Volleyball semi-final.
The 28-26, 23-25, 25-23, 23-25, 18-16 battle lasted two hours and 15 minutes and when it eventually ended, the outpouring of emotion from both sides could not have been more contrasting.
Japan's players raced onto the court, jumping on each other, while China - the Athens 2004 winners - saw players slump to the floor, some of them in tears.
The statistics for both sides could hardly have been tighter. They won three points each on serve and 82 on spike, with Japan blocking 11 times and China 10. The latter made one unforced error more.
Yukiko Ebata and Saori Kimura equally shared 66 points for Japan, while for China Ruoqi Hui scored 26 and the incredible Yimei Wang set aside her injury worries to register 22.
In the other half of the draw, the USA continued to march towards the final after a straightforward victory over the Dominican Republic.
Foluke Akinradewo, Jordan Larson and Destinee Hooker contributed a combined tally of 42 points as the USA moved through, all though they were pushed by the battling Dominicans.
They were on the brink of victory for a considerable period of time in the third set but some wonderful resilience from the Dominicans kept them hanging on.
Up next for the USA is a meeting with the Republic of Korea, who ended the possibility of there being any European involvement in the semi-finals by seeing off Italy in four sets.
Inspired by the faultless Yeon-Koung Kim, who ended the night with 28 points, the Asian side had too much for Massimo Barbolini's women, proving too quick to handle over the course of 105 brilliant minutes.