The 90th Academy Awards crowned Guillermo del Toro's river creature fable "The Shape of Water" best picture at an Oscars that confronted the post-Harvey Weinstein era and sought to pivot to a vision of a more inclusive movie business.

A sense of change was palpable at the ceremony held Sunday at the Dolby Theatre in Los Angeles, where winners made impassioned arguments for gender equality and diversity.

Del Toro's film, which came in with a leading 13 nods, took a leading four awards, including best production design, best score and best director for del Toro.

He became the third Mexican-born filmmaker to win the award, joining his friends and countrymen Alejandro Inarritu and Alfonso Cuaron - who once were dubbed "the Three Amigos."

"The greatest thing that art does, and that our industry does, is erase the lines in the sand," said del Toro, alluding to his international career.

Jordan Peele won for his script to his horror sensation "Get Out," becoming the first African-American to win for best original screenplay. Peele said he stopped writing it "20 times," sceptical that it would ever get made.

"But I kept coming back to it because I knew if someone would let me make this movie, that people would hear it and people would see it," said Peele. "So I want to dedicate this to all the people who raised my voice and let me make this movie."

In a year lacking a clear frontrunner, the awards were spread around. Christopher Nolan's World War II epic "Dunkirk" landed three awards, all for its technical craft: editing, sound editing and sound design.

Inclusion rider

Things went expected in the acting categories, where Frances McDormand won her second Oscar for her performance in "Three Billboards Outside Ebbing, Missouri."

McDormand asked all the attending female nominees to stand up in the theatre.

"Look around, ladies and gentlemen, because we all have stories to tell and projects that need financing," said McDormand.

"I have two words to leave with you tonight, ladies and gentlemen, inclusion rider."

Frances McDormand started a revolution at the #Oscars. Here she is explaining what an “inclusion rider” means. pic.twitter.com/4KSMX54UoJ — Raja Sen (@RajaSen) March 5, 2018

McDormand said all actors are able to insist an "inclusion rider" clause, demanding at least 50 percent diversity among production staff, is included in any contract they sign.

The idea was featured in a TED talk given by Stacy Smith, founder of the Annenberg Inclusion Initiative at the University of Southern California, in 2016.

"A-listers, as we all know, can make demands in their contracts, particularly the ones that work on the biggest Hollywood films. What if those A-listers simply added an equity clause or an inclusion rider into their contract?" she said.

Subbing for last year's best-actor winner, Casey Affleck, in presenting the best-actress award were Jodie Foster and Jennifer Lawrence.

"It's a new day in Hollywood," said Lawrence.

Three widely admired veteran actors won their first Oscars. Gary Oldman won for his Winston Churchill in "Darkest Hour," Allison Janney ("I, Tonya") took best supporting actress, and Sam Rockwell ("Three Billboards") won best supporting actor.

Oldman thanked his "99-years young" mother. "Put the kettle on," he told her. "I'm bringing Oscar home."

But many of the show's most powerful moments came in between the awards.

Ashley Judd, Anabella Sciorra and Salma Hayek - who all made allegations of sexual misconduct against Weinstein - together assembled for a mid-show segment dedicated to the #MeToo movement that has followed the downfall of Weinstein, long an Oscar heavyweight. They were met by a standing ovation.

"We work together to make sure the next 90 years empower these limitless possibilities of equality, diversity, inclusion and intersectionality," said Judd. "That's what this year has promised us."

2018 Academy Awards Winners

Best Picture

"The Shape of Water"

Best Actor

Gary Oldman - "Darkest Hour"

Best Actress

Frances McDormand - "Three Billboards Outside Ebbing, Missouri"

Best Director

Guillermo del Toro - "The Shape of Water"

Best Supporting Actor

Sam Rockwell - "Three Billboards Outside Ebbing, Missouri"

Best Supporting Actress

Allison Janney - "I, Tonya"

Best Original Screenplay

"Get Out"

Best Adapted Screenplay

"Call Me By Your Name"

Best Animated Film

"Coco"

Best Documentary Film

"Icarus"

Best Foreign Language Film

"A Fantastic Woman" - Chile

Best Short Documentary Film

"Heaven is a Traffic Jam on the 405"

Best Live Action Short Film

"The Silent Child"

Best Animated Short Film

"Dear Basketball"

Best Production Design

"The Shape of Water"

Best Costume Design

"Phantom Thread"

Best Cinematography

"Blade Runner 2049"

Best Visual Effects

"Blade Runner 2049"

Best Film Editing

"Dunkirk"

Best Sound Editing

"Dunkirk"

Best Sound Mixing

"Dunkirk"

Best Makeup and Hairstyling

"Darkest Hour"

Original Score

"The Shape of Water"

Original Song

"Remember Me" - Coco