Guillermo del Toro’s monster thriller “The Shape of Water” took the top prize at the Venice Film Festival on Saturday, capping an 11-day event where the demons of social division and environmental disaster loomed large on the screen.

Del Toro was named winner of the Golden Lion by a jury headed by US actress Annette Bening, beating contenders including George Clooney’s “Suburbicon” and Alexander Payne’s “Downsizing.”

The Mexican director said his victory sent a message to “remain pure and stay with your faith, in whatever you have faith in.”

“In my case, it’s monsters,” said the 52-year-old director of films rich in demons and other fantastical creatures, including “Hellboy” and “Pan’s Labyrinth.”

“I have never been a sportsman and this feels like running the marathon and winning,” del Toro said after collecting the trophy. “This movie took six years to get made, so after six years this is the beginning of getting there and feeling the reward and the love of an audience -- in this case the love of a jury and of a festival.”

The victory gives immediate awards-season momentum to “The Shape of Water,” the story of a mute young woman, played by Sally Hawkins, who falls for a mysterious sea creature being held at a high-security lab. Many viewers in Venice fell for the movie’s audacious mix of genres: It’s a monster movie, a Cold War thriller, social-issues drama and even, at times, a musical.

Del Toro said his win was a vindication for monster movies, science fiction and other sometimes derided cinema genres.

“This is a beautiful encouragement, a beautiful act of love, and I think it is something very necessary,” he told reporters. “It’s about time that we understand that you cannot only legitimize certain genres” and not others.

The 74th edition of the world’s oldest film festival brought stars including Clooney, Matt Damon and Jennifer Lawrence to the canal-crossed Italian city’s lush Lido island.

Del Toro’s film was one of several in the lineup that looked anxiously at humanity’s treatment of the Earth and one another.

Similar concerns showed up in the small-town rage depicted in Martin McDonagh’s “Three Billboards Outside Ebbing Missouri”; in the spiritual agonies of Paul Schrader’s eco-drama “First Reformed”; in the migrants fleeing war, drought and hunger in Ai Weiwei’s documentary “Human Flow”; and in “mother!” Darren Aronofsky’s wild parable of Mother Earth under attack.

The festival’s runner-up Grand Jury Prize went to Israeli director Samuel Maoz’s “Foxtrot,” a compelling study of a family’s grief and the way trauma echoes through the generations.

Maoz, who won the Golden Lion in 2009 for his war film “Lebanon,” has received some negative reaction in Israel because “Foxtrot” is critical of the army, the country’s most respected institution.

Maoz said no society could flourish when “critics are considered to be traitors.”

“If I criticize the place I live, I do it because I worry,” he said. “I do it because I want to protect it. I do it from love.”

France’s Xavier Legrand was named best director for his first full-length film “Custody,” which also won the festival’s first-feature prize.

Palestinian stage veteran Kamel El Basha was named best actor for Lebanese director Ziad Doueiri’s drama “The Insult.” Britain’s Charlotte Rampling took the best actress prize for Andrea Pallaoro’s film “Hannah.”

Other winners included Warwick Thornton’s Australian Western “Sweet Country,” which won a Special Jury Prize, and McDonagh’s “Three Billboards Outside Ebbing, Missouri,” which took the trophy for best screenplay.

US actor Charlie Plummer, 18, was named best young performer for portraying a lonely boy who befriends a tired old racehorse in Andrew Haigh’s “Lean on Pete.”

Italian director Susanna Nicchiarelli’s “Nico, 1988,” a biopic of the former Velvet Underground singer Nico, won the Horizons competition, which focuses on newer directors and edgier fare.

Venice has a track record of launching films toward Hollywood awards success. This year’s edition produced a crop of potential acting nominees, including Frances McDormand for “Three Billboards,” Helen Mirren and Donald Sutherland for “The Leisure Seeker” and Lawrence for “mother!”

Venice’s first prize for best virtual reality went to “Arden’s Wake,” a post-apocalyptic story by Eugene Y.K. Chung of the San Francisco-based startup Penrose.

Chung said virtual reality “is where film was 100 years ago, an emerging art form.”

“And it’s going to be a real exciting journey,” he said. (AP)