"Anora", a raw, highly explicit and often hilarious story about a New York erotic dancer, was crowned with the Palme d'Or at the Cannes Film Festival, AFP reported.
It confirmed its director Sean Baker as one of the leading voices of American indie cinema, and promises to make a star of 25-year-old Mikey Madison.
She plays the lead role as a dancer who strikes gold with a wealthy client, only to face the wrath of his Russian oligarch parents.
As head of the jury, "Barbie" director Greta Gerwig praised "Anora" as an "incredible, human and humane film that captured our hearts".
Baker dedicated the film to all sex workers.
"This literally has been my singular goal for the past 30 years, so I'm not really sure what I'm going to do with the rest of my life," he said.
The 77th edition of the festival on the French Riviera saw several highly charged feminist and political movies, and lots of gore and sex.
A trans woman won best actress for the first time, as Karla Sofia Gascon took the award for audacious musical "Emilia Perez" in which she plays a Mexican narco boss who has a sex change.
The jury shared it between Gascon and her co-stars Zoe Saldana and Selena Gomez -- saying they were rewarding the "harmony of sisterhood" -- though only Gascon was at the ceremony.
She dedicated it to "all the trans people who are suffering".
"We all have the opportunity to change for the better, to be better people," she said.
"If you have made us suffer, it is time for you also to change."
There were fewer meaty roles for men this year, but Jesse Plemons took the prize for Yorgos Lanthimos's bizarro series of short stories, "Kinds of Kindness", though he was not present to accept it.
'Deeply sad'
A devastating Iranian film about a family torn apart by the country's recent women-led protests, "The Seed of the Sacred Fig" was given a special jury prize for "drawing attention to unsustainable injustice".
Its director Mohammad Rasoulof, 51, escaped from Iran to avoid a lengthy prison sentence just before the festival.
Rasoulof said his heart was with the film's crew, "still under the pressure of the secret services back in Iran".
"I am also very sad, deeply sad, to see the disaster experienced by my people every day... the Iranian people live under a totalitarian regime," he said.
The second-place Grand Prix went to "All We Imagine as Light", the first Indian entry in 30 years.
It wowed critics with its poetic monsoon-set portrayal of two women who have migrated to Mumbai to work as nurses.
"Emilia Perez" also won the third-place Jury Prize for its French director, Jacques Audiard.
'Revolution'
Best Director went to Portugal's Miguel Gomes for "Grand Tour", an oblique tale about a man abandoning his fiance and travelling around Asia.
Best Screenplay went to "The Substance" starring Demi Moore, an ultra-gory horror film about the pressures women face to maintain bodily perfection as they age.
"What an incredible gift its been to work with you," its writer and director Coralie Fargeat told Moore from the stage.
The film is "about women and what women can still experience in the world. We need a revolution, and I don't think it has really started yet," she said.
"Star Wars" creator George Lucas received an honorary Palme d'Or from his old friend Francis Ford Coppola, who competed this year with the highly divisive "Megalopolis". /BGNES
