Robert Downey Jr. became an Oscar winner on Sunday in a long-awaited victory for the veteran actor who received his first acting nod three decades ago.

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

It was the third overall Oscar nod for one of Hollywood’s most versatile performers but whose career has been marked by extreme setbacks.

“I’d like to thank my terrible childhood” Downey said in a light-hearted speech, pausing for the audience’s laughter, “and the academy — in that order.”

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

'Oppenheimer' wins best picture at Academy Awards, Emma Stone takes best actress

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 on “The View” that he’s grateful he didn’t end up winning in 1993 for best actor for “Chaplin.”

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

Downey also received an Oscar nod in 2008 for a supporting role in “Tropic Thunder.”

Sunday's 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 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.”

‘Oppenheimer’ set to win big at the Oscars

“Oppenheimer,” Christopher Nolan’s three-hour deep dive into the development and fallout of the atomic bomb during World War II, won seven Oscars on Sunday, including best picture, best director for Nolan and best actor for Cillian Murphy. The film entered the night with 13 nominations.

“What we do is meaningful,” Downey said onstage Sunday, “and the stuff we decide to make is important.”