* Documentary depicts lives of people on Rome ring road
* Jury felt "poetic force" of film, jury head says (Adds quote from director, Bertolucci, background)
"Sacro GRA", an Italian documentary about people living along the ring road around Rome, won the Golden Lion for best film on Saturday at the 70th Venice Film Festival.
The film, whose name is a pun on the ring road's name which evokes the Italian for Holy Grail - delves into the lives of a dozen characters, including a weevil-fighting tree scientist.
"I never ever expected to win an award of such importance for a documentary," director Gianfranco Rosi said at the awards ceremony held in the festival's main hall on its closing day.
"I think that all the jury felt the poetic force of Rosi's film and that's all there is to be said," jury president and veteran Italian film director Bernardo Bertolucci said at a news conference.
Rosi's film was one of an unprecedented two documentaries in competition at Venice. The other was American director Errol Morris's "The Unknown Known" about Iraq-era U.S. defense secretary Donald Rumsfeld, which left the festival empty-handed.
The Silver Lion for best director among the 20 entries in the main competition at the world's oldest film festival went to Greece's Alexandros Avranas for "Miss Violence", about a family where the father pimps out his children to make money.
The cup for best actor was awarded to Themis Panou for his performance as the abusive father in "Miss Violence" while the best actress award went to Elena Cotta of Italy for her role in director Emma Dante's "Via Castellana Bandiera", about a stand-off between women drivers in Palermo, Sicily.
Festival director Alberto Barbera had said the line-up of film in the competition emphasised a dark and violent reality, stemming in part from the global economic crisis.
"Sacro GRA" includes shots of sex workers along the ring road, but other films at Venice focused on themes such as incest, family violence, child prostitution and even necrophilia in the James Franco movie "Child of God", which won no awards.
Taiwanese director Tsai Ming-liang, a former Golden Lion winner, landed a Grand Jury Prize for his film "Stray Dogs" about a man and his two children living on the fringes of society in the Taiwanese capital.
Their lives only barely start to become conventional when a mysterious woman, who also feeds stray dogs, brings them under her wing.
"It really was a great competition lineup," Robbie Collin, film critic for The Telegraph of London, told Reuters.
FESTIVAL COMPETITION HEATS UP
Venice may be the world's oldest film festival, but competition among the events is getting ever fiercer. Last month the boutique festival at Telluride, Colorado, screened a "sneak preview" of the new Jonathan Glazer movie "Under the Skin", starring Scarlett Johansson as an alien in human form, before the film had its official premiere in Venice.
"To beat Venice to the punch by a sneak preview of 'Under the Skin' - that was hard on Venice," Collin said..
Toronto, whose film festival overlaps Venice, screens more than 350 films, while Venice had 20 in competition for the Golden Lion and some 40 more in other festival tracks.
"I think that Toronto casts a very wide net and Venice has no interest and no space to compete with that," said Eric J. Lyman, correspondent in Italy for trade publication The Hollywood Reporter.
But he said the Venice award can give a boost even to big-budget productions, like Mexican director Alfonso Cuaron's space disaster drama "Gravity" starring George Clooney and Sandra Bullock which kicked off the festival last week with a bang.