Comic Chris Rock, the host of the ceremony, confronted head-on the row that had engulfed the event ever since the nominees were announced, and his cutting gags were greeted with uncomfortable laughter.
Academy president Cheryl Boone Isaacs – an African-American – struck a more serious tone with a plea for more diversity in the industry. However, a beauty company was forced to apologise when it wrongly identified black actress Whoopi Goldberg as TV host Oprah Winfrey.
When it came to the main awards, Spotlight – the drama about the Boston Globe’s investigative reporting on sexual abuse by Roman Catholic priests – was the surprise winner of the best picture prize and was also named best screenplay.
Best supporting actor winner Mark Rylance, star of Bridge of Spies, Bond theme singer Sam Smith and director Asif Kapadia – the maker of the controversial Amy Winehouse documentary – all grabbed glory for Britain.
Smith found himself embroiled in controversy when he wrongly claimed he was the first “openly gay man” to win an Oscar. Among those to take to social media to correct him was the screenwriter Dustin Lance Black, who won an Academy Award six years ago for Milk.
Jenny Beavan, the British costume designer, who won an Oscar for Mad Max: Fury Road, was sporting a Marks & Spencer jacket weeks after being infamously described as looking like a “bag lady” at the Baftas by host Stephen Fry.
Several dozen protesters had gathered outside the Dolby Theatre in Los Angeles to protest over a second year of all-white acting nominees, while a number of high-profile industry figures, including Spike Lee and Will Smith, had boycotted the ceremony.
In his opening routine, Rock welcomed guests to the “white People’s Choice Awards” and joked that he would not have got the job if presenters had been nominated. He said black people had not protested over the lack of diversity in previous years because they had “real things to protest at the time”.
He added: “They were too busy being raped and lynched to care about who wins best cinematographer. You know, when your grandmother’s swinging from a tree, it’s really hard to care about best documentary foreign short.”
Adressing the race row, Ms Isaacs said: “It’s not enough to just listen and agree, we must take action. While change is often difficult, it is necessary. Dr Martin Luther King once said: ‘The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands at times of challenge and controversy’.”
DiCaprio, who was first nominated for an Oscar 23 years ago, ended years of disappointment by beating Eddie Redmayne, Bryan Cranston, Matt Damon and Michael Fassbender to take home the best actor gong for his role as a 19th-century frontiersman left for dead after being mauled by a bear in The Revenant.
He used his acceptance speech to urge action on climate change, telling the audience: “It’s happening right now, it’s the most urgent threat affecting our entire species, we need to work right now and stop procrastinating.”
Brie Larson, honoured for her role in Room as a young woman kidnapped and imprisoned for years in a shed with her son, said: “Who I was by the time the movie was over was so far from where I started. It was a long process in trying to find myself.”
Spotlight, the underdog in the best picture category, had been nominated for six Oscars, but faced stiff competition from The Revenant and Mad Max: Fury Road – which won six awards – as well as The Big Short, Bridge of Spies, Brooklyn, The Martian and Room.
Michael Sugar, producer of the film, which explored efforts to uncover the scandal of the Catholic church’s efforts to protect paedophile priests, said he hoped its message would “resonate all the way to the Vatican”.
He added: “Pope Francis: it’s time to protect the children and restore the faith.”