Kieran Culkin wins best supporting actor Oscar for 'A Real Pain'

Kieran Culkin won the best supporting actor Oscar on Sunday for playing a motor-mouthed American tourist in "A Real Pain."

A star of the HBO program "Succession," Culkin was a heavy favorite to win after sweeping BAFTA, Critic's Choice, Golden Globe and SAG awards for the movie, which is about two cousins on a Jewish heritage tour of Poland.

"I have no idea how I got here," Culkin said while accepting his award on stage. "I've been acting all my life. I never felt like this was my trajectory."

The movie was also nominated for best original screenplay this year, but missed out on picture and director nods.

Culkin, 42, has also won a Golden Globe for playing Roman Roy on four seasons of "Succession." He played alongside his older brother Macaulay in the "Home Alone" movies, and his younger brother Rory is also an actor.

The lifelong New Yorker's other film roles include "Igby Goes Down," "The Cider House Rules," "Scott Pilgrim vs the World," and the "Father of the Bride" franchise, where he plays the son of Steve Martin and Diane Keaton.

Culkin told New York magazine last year he got cold feet about playing Benji in "A Real Pain," until Emma Stone, a producer on the film and his former girlfriend, convinced him to shoot it.

"It was one of the very, very, very rare scripts that I laughed out loud reading," he said.

Culkin's "Succession" co-star Jeremy Strong - they play brothers on the show - was also up for best supporting actor, for playing Roy Cohn in "The Apprentice."