French-Tunisian director Abdellatif Kechiche's three-hour film set Cannes abuzz with its explicit unsimulated sex scenes and has made a star out of one of its lead actresses Adele Exarchopoulos.
Head of the jury Steven Spielberg, announcing the prize, said the jury was this year taking the unusual step of honouring three people with the award -- Kechiche, Exarchopoulos and the other lead actress Lea Seydoux, who all went on stage to accept the accolade.
The competition was an open field ahead of Sunday's award ceremony. Another forerunner, the quirky comedy Inside Llewyn Davis about a struggling New York folk singer by the American Coen brothers, was named as runner-up.
The award for best actor went to American Bruce Dern, 76, from Alexander Payne's film Nebraska in which he played an aging, alcoholic father on a road trip with his son through the depressed midwestern United States to collect a lottery prize.
French actress Berenice Bejo won the best actress award for playing the wife in Iranian director Asghar Farhadi's tense domestic drama Le Passe (The Past).
"I was not expecting this," said an emotional Bejo. Earlier she had signed autographs on the red carpet in blazing sunshine, a contrast to the festival's opening ceremony on May 15 when umbrellas took over in the rain.
The third prize went to Japanese director Kore-Eda Hirokazu's Soshite Chichi Ni Naru (Like Father, Like Son) while the award for best director went to Mexico's Amat Escalante for his brutal look at Mexico's drug war, Heli.