Gathering just after Colombia played Greece in the southeastern city, the women set up an impromptu pitch using traffic cones for goalposts and played to the enthusiastic cheers of onlookers.
The prostitutes, calling themselves the Naked Football Club -- though in fact they played in the green and yellow uniforms of Brazil -- teamed up with the visiting evangelicals from the United States to take on a local university team in a match with a message.
"Rights must be the same for everyone. We're no different from anyone else just because we're sex workers," player Patricia Bonges told AFP.
"We are finally breaking that prejudice and stigma."
Her American teammate Jenny Jack said the game was about showing that "you just love people, you don't judge, you don't change people, you just love them."
Prostitutes in Brazil have long complained of discrimination and called for the government to treat their profession like any other, including with programs to help older sex workers.
The match was organized by the Prostitutes' Association of Minas Gerais, the state where Belo Horizonte is located.
The association has also helped some of the city's 80,000 sex workers prepare for the World Cup by offering free English classes at a local mall.