American musical "La La Land", directed by Damien Chazelle and starring Ryan Gosling and Emma Stone, kicked off the world's oldest film festival and immediately brought the house down.
Top international film critics, gathered on the glamorous Lido di Venezia for the 10-day fest, cheered the quirky tale of a struggling jazz pianist and his actress girlfriend in Los Angeles, a joyful tribute to the Golden Age of American musicals.
Fellow front-runner "Jackie", Chilean filmmaker Pablo Larrain's potrayal of the days following US president JFK's assassination, wowed thanks largely to a stellar performance from Natalie Portman as Jacqueline Kennedy.
"I felt like it was the most dangerous film I've ever done, because everyone knows what Jackie looked like, sounded like, walked like," Portman admitted to press at the star-studded festival, where A-listers arrived by
Terrence Malick's long-awaited "Voyage of Time: Life's Journey", a documentary on the life and death of the universe, moved critics and the public alike with its use of stunning special effects and real-life images of
earth's most breathtaking creations.
But these glossy, US heavyweights are being challenged by Argentinian directors Gaston Duprat and Mariano Cohn with their comedy "The Distinguished Citizen", about a Nobel Prize-winning author who returns to his village for the first time in 40 years.
Also hot on their heels is Philippine director Lav Diaz's "The Woman Who Left", an acclaimed black and white tale about a wrongly convicted schoolteacher plotting her revenge against the ex-boyfriend who framed her.
The awards ceremony is set to begin at 1700 GMT.
Venice has strengthened its reputation in recent years as a launch-pad for the Oscars -- with "Gravity", "Birdman" and "Spotlight" all premiering here -- and former fashion designer Tom Ford's offering "Nocturnal Animals" may follow suit.
Spooking and stirring in equal part, with arresting performances from US stars Amy Adams and Jake Gyllenhaal as lovers gone awry, the film tells a story within a story about self-harm, love, betrayal and revenge.
The Best Actor award is tipped to go either to Oscar Martinez, who plays the cynical novelist in "The Distinguished Citizen", or Gosling, for his tap-dancing, crooning character in "La La Land".
Amy Adams is in the running for the Best Actress not only for "Nocturnal Animals" but also "Arrival", where her character is all that stands between a group of civilised aliens and the leaders of the world powers, eager to reach for the nuclear button.
Should the jury, lead by British film director Sam Mendes, have a penchant for such tentacled creatures, Mexico's "The Untamed" by Amat Escalante may be in with a shot, with its take on an extraterrestrial who sexually pleasures the brave and foolhardy.
A total of 20 films are competing, including Ana Lily Amirpour's second film "Bad Batch", a cannibal love story with Jim Carrey and Keanu Reeves about a young girl who ends up on the menu in a futuristic United States.
The beautiful "A Woman's Life", by French director Stephane Brize, is tipped to snap up the Silver Lion for Best Direction. The rich period drama, set in 19th century France, tells the tale of a childlike baroness tormented by a rakish local viscount.
The festival has featured dozens of world premiers out of competition, including Italian master Paolo Sorrentino's first TV series "The Young Pope", featuring a brilliantly Machiavellian Jude Law as the Catholic Church's first ever American pope.