LOS ANGELES (Reuters/AFP) - Damien Chazelle became the youngest winner ever of a best directing Oscar on Sunday after picking up the prize for his third feature film, musical La La Land.
It was the first Academy Award for Chazelle, 32, who was the favourite going into Sunday's ceremony after winning Directors Guild and Golden Globe awards earlier this year.
La La Land, a contemporary original musical, is set in Los Angeles and stars Emma Stone and Ryan Gosling as an aspiring actress and a tortured jazz musician who fall in love.
Stone, 28, won her first Oscar for her lead role in the film, beating previous Oscar-winners Natalie Portman and Meryl Streep as well as France's Isabelle Huppert and Irish-Ethiophian Ruth Negga for the accolade.
Casey Affleck won the Best Actor Oscar on Sunday for his role as a grief-stricken father in family drama Manchester By The Sea.
It was the first Oscar for Affleck, 41, the younger brother of Argo director and actor Ben Affleck, 44.
Affleck's understated performance as a taciturn working man who unexpectedly has to look after his teenage nephew beat challenges from Denzel Washington and Gosling to win the Academy Award. He swept awards in the run-up to the Oscars, taking home a Golden Globe and numerous trophies from film critics groups.
An emotional Affleck thanked fellow nominee Washington, whom he credited with being one of the first people to teach him to act, as well as Matt Damon and the film's screenwriter and director, Kenneth Lonergan.
The Manchester By The Sea role was first intended for Damon, a Boston childhood friend of Casey and Ben Affleck. Damon had to step down because of other commitments. "I'm really proud to be part of this community," Affleck said. "I'm just dumbfounded that I'm included."
Chazelle thanked his girlfriend, actress Olivia Hamilton, while accepting his statuette. "This was a movie about love and I was lucky enough to fall in love while making it," he said.
It took six years for him to find a studio willing to finance and take a gamble on the film, which was conceived as a modern take on 1940s and 1950s Hollywood musicals. He also wrote the screenplay.
In 2015, Chazelle was nominated for a Best Adapted Screenplay Oscar for his breakout film Whiplash, about a young jazz drummer. That success helped catapult La La Land into production.
He took the Oscar on Sunday over a field that included Denis Villeneuve for Arrival, Mel Gibson for Hacksaw Ridge, Kenneth Lonergan for Manchester By The Sea, and Barry Jenkins for Moonlight.