Cannes, France ? The French film “The Class,” a frank tale about classroom life using real students and teachers at a junior high school, won top honors Sunday at the Cannes Film Festival.

Directed by Laurent Cantet, “The Class” (“Entre les Murs”) was the first French film to win the main prize, the Palme d’Or, at Cannes since “Under Satan’s Sun” in 1987. The docudrama was shot in a raw, improvisational style to chronicle the drama that unfolds over one school year.

The win was a unanimous decision among the nine-member Cannes jury, said Sean Penn, who headed the panel.

“The movie that we wanted to make had to resemble French society, had to be multifaceted, a bit teeming, complex, and had to sometimes portray frictions that the film didn’t try to erase,” Cantet said.

Benicio Del Toro won the best-actor prize for “Che,” Steven Soderbergh’s four-hour-plus epic about Latin American revolutionary Che Guevara. Presented as two films, “Che” follows Guevara and Fidel Castro’s triumphant guerrilla campaign to overthrow Cuba’s government in the late 1950s and Guevara’s downfall and execution after trying to foment a similar rebellion in Bolivia in the 1960s.

Sandra Corveloni was chosen as best actress for “Linha de Passe,” in which she plays the mother of four brothers struggling to make better lives for themselves in a Brazilian slum. It was her first role in a feature film.

The Cannes jury awarded special prizes to Clint Eastwood, who directed the competition film “Changeling,” and Catherine Deneuve, who appeared in two films at Cannes this year.

Eastwood was shut out for key prizes with “Changeling,” his warmly received missing-child drama starring Angelina Jolie.