An angry shopper lobbed a huge trolley at a woman's head after a row as they queued up to pay for their groceries.
Things got out of hand after the man, 36, claimed the victim was harassing him and then made false remarks about his sexuality.
Shocking CCTV footage shows him lifting up the empty orange metal trolley.
As the woman, who appears to talking on her phone, takes her eyes off him he quickly hurls it at her head knocking her to the ground.
Other shoppers approach the man to calm down the situation and assist the dazed shopper.
The woman is seen moving on the floor as the video comes to an end.
It happened at an Atacad o Dia a Dia supermarket in Santo Antônio do Descoberto Brazil.
He told the 45-year-old woman: "What I did was to serve as a lesson."
The unnamed man accused the woman of harassing him and calling him 'gay'.
The police confirmed that the pair did not know each other prior to the incident.
A case has been opened for minor bodily injury and the suspect was released after leaving a statement.
The victim received medical treatment for minor injuries and was subsequently discharged from the hospital.
Supermarket bosses said they condemn all forms of violence and have offered their support to the victim.
The investigation is ongoing.
Elsewhere in Brazil this week, seven people were killed including a 12-year-old girl, after two gunmen went on a rampage at a pool hall after people mocked them for losing a game.
The men lost two consecutive games in Sinop City, in the state of Mato Grosso, on Tuesday, and went ballistic when the other players laughed at them for losing, Newsflash reported.
The chilling footage shows one of the men lining up the victims against the wall in preparation for an execution-style shooting, while the other grabs a shotgun from a pickup truck.
In a matter of seconds, the people who were enjoying their afternoon of pool playing are all dead on the ground.
The first man in a white T-shirt is shot at point-blank range while the other man joins in with his handgun.
One woman is seen holding up her arms as the gunmen leave the scene of the massacre, it is understood only a few survived.
The murderers eventually flee the scene, grabbing small amounts of cash on pool tables, as well as a woman’s purse.
The six who died instantly were identified as Larissa Frasao de Almeida, 12, Orisberto Pereira Sousa, 38, Adriano Balbinote, 46, Getulio Rodrigues Frasao Junior, 36, Josue Ramos Tenorio, 48, and Maciel Bruno de Andrade Costa, 35.
A seventh, Elizeu Santos da Silva, 47, was pronounced dead later.
