The cast and crew of "Oppenheimer" accept the award for best picture during the Oscars on March 10, 2024, at the Dolby Theatre in Los Angeles. (PHOTO / AP)

LOS ANGELES - Oppenheimer,  the blockbuster biopic about the race to build the first atomic bomb, claimed seven Academy Awards including the prestigious best picture trophy on Sunday as Hollywood celebrated a triumphant year in film.

Irish actor Cillian Murphy won best actor for playing theoretical physicist J. Robert Oppenheimer, leader of the US effort in the 1940s to create a weapon that ended World War II. Oppenheimer director Christopher Nolan took home the directing Oscar.

Cillian Murphy accepts the award for best performance by an actor in a leading role for "Oppenheimer" during the Oscars on March 10, 2024, at the Dolby Theatre in Los Angeles. (PHOTO / AP)

"We made a film about the man who created the atomic bomb, and for better or worse we are living in Oppenheimer's world," Murphy said as he held his trophy on stage. "So I would really like to dedicate this to the peacemakers everywhere."

A three-hour historical drama about science and politics, Oppenheimer became an unlikely box office hit and grossed $953.8 million, in addition to widespread critical praise.

British director Christopher Nolan poses in the press room with the Oscars for Best Director and Best Picture for "Oppenheimer" during the 96th Annual Academy Awards at the Dolby Theatre in Hollywood, California on March 10, 2024. (PHOTO / AFP)

It was the first of Nolan's films to win best picture. The director has previously won acclaim for The Dark Knight Batman trilogy, Inception, Memento and other movies.

As he accepted his gold statuette, Nolan noted that the movie business was a century old and still evolving.

"To know you think I'm a meaningful part of this means the world to me," he said.

Emma Stone poses with the award for best performance by an actress in a leading role for "Poor Things" at the Governors Ball after the Oscars on March 10, 2024, at the Dolby Theatre in Los Angeles. (PHOTO / AP)

Emma Stone wins best actress

Emma Stone was named best actress for playing a woman revived from the dead in the dark and wacky comedy Poor Things. It was the second Academy Award for Stone, who landed the best actress honor for 2016 musical La La Land.

"This is really overwhelming," she said on stage.

The best actress race had been considered one of the tightest competitions with Lily Gladstone nominated for Killers of the Flower Moon. Had she prevailed, Gladstone would have been the first Native American to win an acting Oscar.

US actor Robert Downey Jr poses in the press room with the Oscar for Best Actor in a Supporting Role for "Oppenheimer" during the 96th Annual Academy Awards at the Dolby Theatre in Hollywood, California on March 10, 2024. (PHOTO / AFP)

In supporting actor categories, Robert Downey Jr of Oppenheimer and The Holdovers star Da'Vine Joy Randolph claimed their first Academy Awards.

Downey, who was nominated for an Oscar in 1993 before his career was derailed by drug use, won his honor on Sunday for playing Oppenheimer's professional nemesis, Lewis Strauss.

"I'd like to thank my terrible childhood and the Academy, in that order," Downey joked before he saluted his wife Susan, who he said found him as a "snarly rescue pet" and "loved him back to life".

Da'Vine Joy Randolph accepts the award for best performance by an actress in a supporting role for "The Holdovers" during the Oscars on March 10, 2024, at the Dolby Theatre in Los Angeles. (PHOTO / AP)

Randolph received the best supporting actress trophy for playing a grieving mother and cafeteria worker in the comedy set in a New England boarding school.

"For so long, I always wanted to be different, and now I realize I just need to be myself," she said. "I thank you for seeing me."

British Holocaust drama The Zone of Interest was named best international feature, and Anatomy of a Fall won best original screenplay.

The Boy and the Heron, Japanese director Hayao Miyazaki's semi-autobiographical film about grief, was named best animated feature.

ALSO READ: 'Oppenheimer' wins again with top film prize at PGA Awards

Winners were chosen by the roughly 10,500 members of the Academy of Motion Picture Arts & Sciences.

After 2023 was marred by labor strikes by actors and writers, the Oscars gave Hollywood a chance to celebrate two blockbusters, Oppenheimer and Barbie, which brought in a combined $2.4 billion at theaters and made movies the center of pop culture last summer.

French director and screenwriter Justine Triet and Arthur Harari pose in the press room with the Oscar for Best Original Screenplay for "Anatomy of a Fall" during the 96th Annual Academy Awards at the Dolby Theatre in Hollywood, California on March 10, 2024. (PHOTO / AFP)

Barbie ended the night with one Oscar.

Billie Eilish and Finneas O'Connell landed best original song for the ballad What Was I Made For? The pair had performed the song on stage earlier with Eilish singing at a microphone next to O'Connell, her brother and co-writer, on piano.

US singer-songwriter Billie Eilish (right) and US singer-songwriter Finneas O'Connell accept the award for Best Original Song for "What Was I Made For" from "Barbie" onstage during the 96th Annual Academy Awards at the Dolby Theatre in Hollywood, California on March 10, 2024. (PHOTO / AFP)

Ryan Gosling donned a hot pink suit, gloves and a cowboy hat to belt out rock ballad I'm Just Ken, surrounded by male dancers dressed in black.

On the red carpet, stars strutted in strong silhouettes, sparkles and a splash of Barbie-inspired pink.

Canadian actor Ryan Gosling (left) and British-US musician Slash perform "I'm Just Ken" from "Barbie" onstage during the 96th Annual Academy Awards at the Dolby Theatre in Hollywood, California on March 10, 2024. (PHOTO / AFP)

Talk show host Jimmy Kimmel, hosting the show for the fourth time, opened the ceremony by complimenting, and taking jabs at, many of the nominees and their films.

The comedian praised Barbie, the pink-drenched doll adventure, for remaking a "plastic doll nobody even liked anymore" into a feminist icon.

Host Jimmy Kimmel speaks during the Oscars on March 10, 2024, at the Dolby Theatre in Los Angeles. (PHOTO / AP)

Before the film, there was "a better chance of getting my wife to buy our daughter a pack of Marlboro Reds" than a Barbie, Kimmel said on the broadcast, which was shown live on the US ABC network.

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Kimmel said many of this year's movies were too long, particularly Martin Scorsese's 3-1/2-hour epic Killer of the Flower Moon about the murders of members of the Osage Nation in 1920s Oklahoma.

"In the time it takes you to watch it, you could drive to Oklahoma and solve the murders," Kimmel joked.