Elsewhere at the ceremony - which took place at Los Angeles" Dolby Theatre and was hosted by Jimmy Kimmel - "Darkest Hour" star Gary Oldman took home the award for Performance by an Actor in a Leading Role, while Frances McDormand caused a stir when she asked all the female nominees in the room to stand as she picked up the Performance by an Actress in a Leading Role honour for "Three Billboards Outside Ebbing, Missouri'.
"The Shape of Water" on March 4 won top honors at the Oscars including the coveted best picture statuette, bringing the curtain down on a Hollywood awards season overshadowed by scandal over sexual misconduct in showbiz.
On stage, del Toro said in the acceptance speech: "I want to dedicate this to every young filmmaker, the youth that is showing us how things are done". The film's studio, Fox Searchlight, has denied the allegations.
Sam Rockwell, Jane Fonda, Patrick Stewart and Steven Spielberg were among the attendees to sport Time's Up pins on their evening wear.
As expected, Britain's Gary Oldman won his first Oscar for playing World War Two leader Winston Churchill in Warner Bros.'"Darkest Hour," while Frances McDormand's woman in a vengeful fury was a popular best actress victor for Fox Searchlight's dark comedy "Three Billboards Outside Ebbing, Missouri". He noted that if push came to shove, you could maybe say 2011's The Artist had a female lead, but "the Academy didn't", which is an important distinction.
This was the first Oscar nomination and win for Austerberry and production design teammates Jeffrey A. Melvin and Shane Vieau.
Trump vs. Jeff Sessions
Trump's tweet on Wednesday, however, suggests his patience with this thread of his defense might be running out. Instead, Trump is turning to his tried-and-true Twitter technique of taunting Jeff Sessions .
I owe this and so much more to so many.
The actor also sent out a special thank you to his mother.
Greta Gerwig, only the fifth woman in Oscars history to be nominated for best director - for comedy/drama "Lady Bird" - however went home empty-handed, despite other nominations for best picture and best screenplay.
She said: "Meryl (Streep), if you do it, everyone else will".
"We all have stories to tell and projects we need financed", she said to enthusiastic applause.
"Don't talk to us about it at the parties tonight, invite us into your office, we'll tell you all about them".