Leonardo DiCaprio finally won an Oscar on Sunday, taking home the best actor statuette for his role in revenge movie "The Revenant."DiCaprio, 41, had been nominated four times previously for an acting Oscar over a career spanning 25 years. He was the favorite to clinch the Academy Award this year for his grueling portrayal of a fur trapper left for dead in an icy wilderness after being mauled by a bear.In a fight for survival, his "Revenant" character Hugh Glass treks through snow-covered forests, gets swept away in a waterfall, sleeps inside the carcass of a disemboweled horse and hungrily eats raw bison liver before making it back to his camp.DiCaprio, a bachelor with a string of supermodel girlfriends, has matured into one of the world's most admired and popular actors, as well as a champion of environmental causes ranging from marine reserves to the rights of indigenous people.In his acceptance speech, DiCaprio, who received a standing ovation, said: "Let us not take this planet for granted. I do not take tonight for granted."DiCaprio added: "Our production needed to move to the southern tip of this planet to find snow. Climate change is real, it is happening now. It is the most urgent threat facing our entire species and we need to work collectively together, and we need to support leaders around the world who do not speak for the big polluters and the big corporations but who speak for all of humanity."DiCaprio had already won Golden Globe and Screen Actors Guild trophies for the role, which transformed the heartthrob from movies like "Titanic" and "Romeo + Juliet" into a greasy-haired 1820s fur trapper who barely speaks after the bear ripped his throat.DiCaprio won his first Oscar nomination in 1994 for his supporting role as a mentally challenged boy in "What's Eating Gilbert Grape."His romantic "Romeo + Juliet" and "Titanic" roles went unrecognized by the Academy of Motion Picture Arts and Sciences, and it was another 10 years before his obsessive-compulsive Howard Hughes in "The Aviator" brought a second Oscar nomination.Nominations for 2006's "Blood Diamond" and 2013's "The Wolf of Wall Street" came and went without DiCaprio taking home the most coveted trophy in show business.Following is a list of winners in key categories for the Oscar awards: BEST PICTURE"Spotlight"BEST DIRECTORAlejandro Iñárritu, "The Revenant"BEST ACTORLeonardo DiCaprio, "The Revenant"BEST ACTRESSBrie Larson, "Room"BEST SUPPORTING ACTORMark Rylance, "Bridge of Spies"BEST SUPPORTING ACTRESSAlicia Vikander, "The Danish Girl"BEST ORIGINAL SCREENPLAY"Spotlight"BEST ADAPTED SCREENPLAY"The Big Short"BEST ANIMATED FEATURE FILM"Inside Out"BEST DOCUMENTARY FEATURE"Amy"BEST FOREIGN LANGUAGE FILM"Son of Saul" HungaryBEST ORIGINAL SCORE"The Hateful Eight" Ennio MorriconeBEST ORIGINAL SONG"Writing's On The Wall" from "Spectre" ▄