On a night dominated by Mad Max: Fury Road with a record six Oscars, the investigative journalism drama Spotlight has surprisingly won best picture at the 88th Academy Awards.

With survival epic The Revenant highly favoured to claim the top prize, director Tom McCarthy's potent drama about the Boston Globe investigation into the Catholic Church's cover-up of sexual abuse was a topical win considering Cardinal Pell's testimony to the Royal Commission from the Vatican.

"This film gave a voice to survivors," said McCarthy. "This Oscar amplifies that voice which we hope will become a choir that will resonate all the way to the Vatican. Pope Francis, it's time to protect the children and restore the faith."

Mexican director Alejandro Gonzalez Inarritu won back-to-back best director awards for The Revenant after Birdman last year, with the movie's star, Leonardo DiCaprio, claiming best actor – his first Oscar win from six previous nominations.

A politically charged Oscars was dominated by Chris Rock's sharp barbs about Hollywood's lack of racial diversity. At what he called the "white Peoples Choice Awards", Rock noted the #OscarsSoWhite protests were notably absent in the 1950s and '60s.

"We had other things to protest," he said. "We were too busy being raped and lynched to care about who won best cinematographer. When their grandmother is swinging from the tree, it's really hard to care about best documentary foreign short."

Rock said that with no black acting nominees, the question everyone was asking was whether Hollywood was racist.

"Is it 'burning cross' racist? No," he said. "Is it 'fetch me lemonade' racist? No ...

"Hollywood is sorority racist. It's like 'we like you Rhonda but you're not a Kappa.'

"But things are changing. We got a black Rocky this year. Some people it Creed. I call it Black Rocky."

While Fury Road missed out on the top two awards, director George Miller's action movie dominated the early Oscars.

Inside 90 minutes, it won six Oscars – best costume design (Jenny Beavan), production design (Colin Gibson and Lisa Thompson), editing (Margaret Sixel), make-up and hairstyling (Lesley Vanderwalt, Elka Wardega and Damian Martin), sound editing (Mark A. Mangini and David White) and sound mixing (Ben Osmo, Chris Jenkins and Gregg Rudloff).

With 11 Australians winning and Fury Road overtaking The Piano's three awards, it was a record haul at the Oscars. It was a remarkable night for a movie that required Miller to overcome multiple setbacks over 12 years to even reach the screen.

"It took enormous creative courage and guts to make this film," Sixel said. "So I just want to say thanks to George Miller [her husband and the film's producer-director] and [producer] Doug Mitchell and the whole crew that endured six months in that Namibian desert to bring back the most amazing footage."

Gibson described the Oscar for production design as a win for diversity.

"To get one of these, you've got an idea of the multitudes of Australians, New Zealanders, Brits, Americans, South Africans, Namibians who all came together under George's vision to bring you a tale about a man with mental health issues, an amputee amazon and five runaway sex slaves," he said.

"So I'd like to chalk this one up as the first Oscar for diversity."

Since the turn of the century, only three movies have won more Academy Awards than Fury Road - The Lord of the Rings: The Return of the King with 11, Slumdog Millionaire with eight and Gravity with seven. The Hurt Locker and Chicago also won six Oscars.

The other Australian nominee – Cate Blanchett for Carol – missed out when Brie Larson won best actress for playing an imprisoned mother with a young son in Room.

In another upset, Mark Rylance from Bridge of Spies beat favourite Sylvester Stallone from Creed to win best supporting actor.

Delivering one of the night's best speeches, the English actor praised director Steven Spielberg as "one of the greatest storytellers of our times".

"Unlike some of the leaders we're being presented with these days, he leads with such love that he's surrounded by masters in every craft on this film – every craft – not the least Mr Tom Hanks," he said.

Rylance said acting with Hanks clearly helped.

"I don't know how they separate the five of us from all the other supporting actors who are making films at the moment," Rylance said. "It's a wonderful time to be an actor."

Alicia Vikander, who played the artist wife of a gender-changing painter in The Danish Girl, won best supporting actress despite clearly being the female lead in the film.

"Thank you so much for your support and belief in me," she said of director Tom Hooper. She also thanked co-star Eddie Redmayne "for being the best acting partner," adding: "I could not have done it without you. You raised my game."

There were two other striking political moments during the Oscars.

First Lady Gaga received a standing ovation after performing her nominated song from the documentary The Hunting Ground, about sexual assault in American colleges, surrounded by 50 survivors of rape.

She sang Til It Happens To You, written with Diane Warren, surrounded by women and some men with the likes of "Not your fault" and "Survivor" written on their arms.

Then DiCaprio, after winning best actor, called for action on climate change to oppose what he called the politics of greed.

He noted that while filming in 2015 – "the hottest year in recorded history" – The Revenant had to move to the southern tip of the planet to find snow.

"Climate change is real," he said. "It's happening right now. It's the most potent threat facing our entire species and we need to work collectively together and stop procrastinating."

When Inarritu won his fourth Oscar in two years – on top of producing, directing and writing Birdman - he added to the strong call for more recognition for racial issues when he quoted a line from The Revenant's script.

"There's a line in the film that says: Glass says to his mixed-race son 'they don't listen to you, they just hear the colour of your skin'" Innaritu said. "So what a great opportunity to our generation to really liberate ourselves from all prejudice and this tribal thinking and make sure, once and forever, that the colour of the skin becomes as irrelevant as the length of our hair."

The widely panned Bond theme song, Writing's on the Wall from Spectre, surprisingly won best original song. An emotional Sam Smith, who sang and co-wrote the song, said he had read recently that no openly gay man had a ever won an Oscar and dedicated the award to the LGBT community.

"I stand here tonight as a proud gay man and I hope we can all stand together as equals one day," he said.

In fact, Australian animator Adam Elliot thanked his boyfriend when he won best animated short with Harvie Krumpet more than a decade ago.

Veteran Italian composer Ennio Morricone won best original score for The Hateful Eight. While he won an honourary Oscar in 2007, it was the 87-year-old's first win from five previous nominations for Days of Heaven, The Mission, The Untouchables, Bugsy and Malena.

The Oscar for best foreign-language film went to Son of Saul, the acclaimed Hungarian Holocaust drama directed by Laszlo Nemes.

"Even in the darkest hours of mankind, there might be a voice within us which allows us to remain human," Nemes said. "That's the hope of this film."

Best feature documentary went to Asif Kapadia and James Gay-Rees for Amy, about singer Amy Winehouse.

Kapadia, previously best known for Senna, said they wanted to make a film that showed who Winehouse really was - "a beautiful girl, an amazing soul, funny, intelligent, witty, someone special, someone who needed looking after."

There was another potent political moment when Sharmeen Obaid-Chinoy's A Girl In the River: The Price Of Forgiveness, about a woman who survived an honour killing in Pakistan, won best short documentary short subject.

"This is what happens when determined women get together," Obaid-Chinoy said. "This week the Pakistani prime minister has said that he will change the law on honour killing after watching this film. That is the power of film."

Winner of the Oscar for best live-action short was Benjamin Cleary and Serena Armitage's Stutterer.

"Every day is a proud day to be Irish but today more than usual," said Cleary.

The Oscar for best animated feature went to Pixar's inventive Inside Out, with best animated short going to Bear Story from Gabriel Osorio Vargas and Pato Escala Pierart. According to the directors, it is the first win at the Academy Awards for a film from Chile.

Best visual effects surprisingly went to the sci-fi film Ex Machina considering Star Wars: The Force Awakens had been favourite to win.

In another Mexican triumph, Emmanuel Lubezki won best cinematography for the third consecutive year – for Gravity, Birdman and now The Revenant.

Winner of best adapted screenplay was The Big Short, written by Charles Randolph and Adam McKay, who thanked the Hollywood studio Paramount for taking a risk on a movie about "financial esoterica" and introduced a sharp political note when he said: "If you don't want big money to control government, don't vote for candidates that take money from big banks or weirdo billionaires."

Sharp straight off the bat ... Chris Rock. Photo: Getty Images.