Cameroon shocked Brazil with a last-gasp 1-0 victory but still exited the FIFA World Cup, and Twitter was sent into a frenzy.
Selecao boss Tite made several changes to his starting lineup for the game, bringing in fringe players such as Gabriel Jesus and Fabinho.
Brazil dominated much of the game, boasting 21 shots to Cameroon's seven, and had a 65% share of the possession.
Tite's men peppered Cameroon goalkeeper Devis Epassy's goal, but it was Lions indomitables who stole a dramatic winner.
Ngom Mbekeli sped down the right flank before firing a perfect cross into the Brazilian box.
Vincent Aboubakar was there to meet it and headed home a sensational 90+2nd minute winner.
He threw his shirt off in delight as he celebrated his goal, with Cameroon becoming the first side to score against Selecao at the 2022 FIFA World Cup.
Aboubakar was subsequently sent off for his celebrations as he was already on a yellow card.
However, he smiled as he exited the pitch, as did the referee when giving him the red card.
The win was not enough for the Africans following Switzerland's pulsating 3-2 victory over Serbia.
Brazil head into the last 16 as Group G winners, while the Swiss qualify in second place.
Tite's side will face South Korea in the next round, but they may be concerned by how they suffered their first defeat of the FIFA World Cup.
Here are some reactions from fans on Twitter to a memorable night for Cameroon:
Brazil's Antony claims that the air conditioning at the FIFA World Cup is making players ill
Antony started Brazil's 1-0 defeat to Cameroon but has been dealing with illness during the FIFA World Cup campaign in Qatar.
He has touched on how the air conditioning units are affecting players at the tournament, saying (via Daily Mail):
"It was a bit difficult. I ended up having a bad feeling there for a few days that complicated me a bit. I'm recovering well and getting 100 per cent. It was more of a sickness, throat. It was the air conditioning (in the stadiums)."
Selecao fans will be hoping all of their squad are in top condition when they face South Korea on Monday, 5 December.
The Asian side qualified for the last 16 dramatically following a 90+1st minute winner against Portugal to claim a 2-1 win.