First-time director Jim Cummings on Saturday scooped the Grand Prize at France's Deauville American Film Festival for "Thunder Road", a tragicomedy about a Texas single father.
President of the jury actress Sandrine Kiberlain praised 31-year-old Cummings' film in which he also stars as "offbeat and so inventive, written, acted and directed by an outstanding young man", adding that it was a work "unlike any other".
"What a joy to witness the birth of an artist, the arrival of a comet," she said.
The jury unusually awarded two Jury Prizes to "Night Comes On", a first film by Jordana Spiro and "American Animals" also a first film by Bart Layton.
The Deauville festival in the Normandy seaside resort was launched in 1975 as a celebration of American movies.