The decisive moment came in the 91st minute when Coventry City winger Tatsuhiro Sakamoto bundled the ball into the net to give Japan a memorable victory. Brazil players immediately appealed for a foul in the build-up, arguing that Aston Villa midfielder Joao Gomes had been dispossessed illegally.
The protests continued after the goal, with Ancelotti and Raphinha dismissed on the touchline. Tensions escalated further after the final whistle, forcing security personnel to intervene and separate several Brazilian players from the match officials, including Singaporean referee Jansen Foo.
Ancelotti explained that he received a red card because the referee believed he had failed to control his technical area, with several players entering the pitch during the protests.
The Italian manager also questioned the referee's handling of the encounter, suggesting that the official lacked the experience required for a match of such intensity.
"The result, obviously, was influenced by the referee's performance," Ancelotti said, while adding that he did not believe the official was entirely responsible for the controversy.
Brazil had initially found themselves in a difficult position after Japan raced into a 2-0 lead within the opening 19 minutes. Takefusa Kubo opened the scoring before Keito Nakamura doubled the advantage, putting the Asian side firmly in control.
However, Real Madrid forward Vinicius Junior inspired Brazil's response, scoring twice to bring his team back into the contest. His second goal was particularly impressive, as he produced a beautifully curled finish to restore parity.
Brazil had also been frustrated earlier in the match when appeals for a penalty following a challenge on Raphinha were rejected. Both the Barcelona winger and Ancelotti reacted angrily to the decision, with their frustration continuing throughout the encounter.
Raphinha had already been substituted when he was dismissed, having confronted the fourth official while leaving the field.
The defeat marked Brazil's second 3-2 friendly loss against Japan in the past 18 months. The two nations also faced each other in the last 32 of this summer's World Cup, where Brazil secured a 2-1 victory.
