Joaquin Phoenix wins best actor Oscar for "Joker" and delivers powerful acceptance speech

Joaquin Phoenix's visceral portrayal of a troubled man's descent into villainy in "Joker" earned him his first Oscar in a career that has seen personal and professional highs and lows. "I've been a scoundrel in my life. I've been selfish, I've been cruel at times and hard to work with ... but so many of you in this room have given me a second chance," Phoenix said in accepting the award Sunday night.

When people guide each other toward redemption, he said, "that is the best of humanity."

In sometimes-rambling remarks, Phoenix addressed gender and ethnic inequality and even the treatment of dairy cows. He wrapped it all in hopeful words, both his own and those of his late brother, actor River Phoenix.

"Human beings at our best are so inventive and creative and ingenious. I think when we use love and compassion as our guiding principles we can ... create systems of change beneficial to all sentient beings and the environment," Phoenix said. "When he was 17, my brother wrote this lyric: 'Run to the rescue with love, and peace will follow."'

He was in a bit of a daze with tears in his eyes when he walked offstage. Looking down at his Oscar he asked, "Whose is this?"

"It's yours," said the woman escorting him out.

Phoenix was nominated twice before for lead actor, for 2012's "The Master" and his performance as Johnny Cash in 2005's "Walk the Line." He received a supporting bid for 2000's "Gladiator."