A post-match altercation between two soccer clubs in Brazil escalated so quickly -- a policeman actually fired a rubber bullet at a player's leg from point-blank range ... and the wild scene was all caught on video.

It happened after a regional club match between Grêmio Esportivo Anápolis and Centro Oeste on Wednesday night. After Centro took home a 2-1 victory ... a scuffle broke out between the two sides, according to Brazilian newspaper Globo.

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A short time later, police got involved ... and the situation went sideways. In a video from the scene ... you can see one of the law enforcement members shove away a player before pointing a non-lethal weapon at the group. Suddenly, a rubber bullet was fired ... striking Grêmio Anápolis goalkeeper Ramón Souza in the thigh.

The goalie immediately limped away from the area as the officer seemingly taunted him. Souza received medical attention on the field for excessive bleeding ... and was transported to a local hospital.

The club condemned the act in an Instagram post and called for the responsible parties to be held accountable.

"A horrible, unbelievable and criminal act by someone who should care about the safety and integrity of the people who were there at the Jonas Duarte Stadium," the team wrote.

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The team also updated Souza's condition ... saying he is not at risk of losing his life or losing his leg.

As for police, they said they're investigating the incident.