Three decades after receiving his first Academy Award nomination, Robert Downey Jr. has won his first Oscar.

Downey won best supporting actor on Sunday for his portrayal of Rear Adm. Lewis Strauss in “Oppenheimer,” hailed as one of Downey's best performances in years.

It was the third career Oscar nomination for a veteran actor known as one of Hollywood's most versatile performers but before Sunday had never won an Academy Award. He was nominated in 1993 for best actor for “Chaplin” and in 2008 for best supporting actor in “Tropic Thunder.”

Downey gave a light-hearted speech as he accepted his award.

“I'd like to thank my terrible childhood” he said, pausing for the audience's laughter, “and the academy, in that order.”

He also thanked his wife, Susan. “You loved me back to life and that's why I'm here.”

“Oppenheimer,” Christopher Nolan's three-hour deep dive into the development and fallout of the atomic bomb during World War II, led the Academy Awards with 13 nominations.

Downey beat Sterling K. Brown for “American Fiction,” Ryan Gosling for “Barbie,” Mark Ruffalo for “Poor Things” and Robert De Niro for “Killers of the Flower Moon.”

The win solidified Downey's frontrunner status this awards season. He also took home the top honor for supporting actor at the Golden Globes, BAFTA Film Awards, SAG Awards and Critics Choice Awards.

“Why me? Why now? Why do things seem to be going my way?” he said while accepting his SAG Award.

Downey has been open about his past struggles with drug addiction. He revealed in his 2022 documentary “Sr.,” which pays tribute to his filmmaker father, that he was addicted to drugs by age 8.

A series of arrests for drug-related charges and a year in prison followed Downey's first Oscar nod 30 years ago, when he was 28.

The actor said recently that he's grateful he didn't end up winning in 1993.

“I was young and crazy," he said on “The View.” “It would have put me under the impression that I was on the right track.”