CANNES, France (AFP) - A black-and-white film about a real-life Finnish boxer, The Happiest Day In The Life Of Olli Maki, won the top prize of the "Un Certain Regard" section of the Cannes film festival on Saturday.

The first feature by director Juho Kuosmanen tells the story of the build-up to a world featherweight championship title match in 1962, when Maki fought the American Davey Moore.

But he is distracted by falling in love and ended up being beaten by Moore in the second round of the fight.

"I am totally surprised and happy," Kuosmanen told reporters, who has previously worked in theatre and opera.

"This is the very first festival that I've ever been to."

American Matt Ross took the director's prize for Captain Fantastic, starring Viggo Mortensen as the head of an eccentric family of brilliant home-schooled children.

Mortensen made headlines at Cannes for playfully giving photographers the finger at its premiere.

Harmonium by Japanese director Koji Fukada, about a family shattered by a visitor who comes to live with them, won the jury prize, with a special prize going to the Dutch-Japanese animated film The Red Turtle by Michael Dudok De Wit.

Delphine and Muriel Coulin won the screenplay award for The Stopover, their film about French soldiers returning from Afghanistan.

The festival's main awards, including its top prize the Palme d'Or, will be announced on Sunday after a star-studded closing ceremony in Cannes.