Allison Janney won her first Oscar for best supporting actress on Sunday night, sweeping the major awards shows with her unflinching portrayal of Tonya Harding’s abusive mother in “I, Tonya.”

“I did it all by myself,” Janney joked at the opening of her acceptance speech. “Okay, nothing further from the truth.”

She then thanked the Academy and her fellow nominees who “represent everything that is good and right and human about this profession.”

The actress said she was grateful to “I, Tonya” screenwriter Steven Rogers.

“Thank you for the gift of LaVona. I did not see this coming, you did. You give new meaning to the word friend.”

Janney also recognized her “I, Tonya” family (“a cast and crew and bird that elevated my work”), as well as Neon and 30 West.

“Joanne Woodward, thank you for your encouragement and generosity that gave me the confidence to think I could pursue a career in acting. To my mother and father, Jay; my family; my family of friends; the staff. I love you. And this is for Hal. You are always in my heart. Thank you very much.”

Backstage, Janney, the longtime television actress, told reporters that she hadn’t allowed herself to dream about one day winning an Oscar.

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“I kind of didn’t dare to dream of things like this because I didn’t want to be disappointed,” she said. “At a certain point I had given up. I wasn’t getting the roles in film that would get me attention like this.”

Janney added that despite her big Oscar win, she would be back at work Monday morning. “I have to be at a table read tomorrow morning,” she said. “I am going right back to work. I am so happy I have job to go to because it can go to your head.”

The Oscar win continues her awards show sweep this year, with honors that include a Golden Globe, a BAFTA, a SAG Award, and an Independent Spirit Award.

Janney beat out Mary J. Blige for “Mudbound,” Lesley Manville for “Phantom Thread,” Laurie Metcalf for “Lady Bird,” and Octavia Spencer for “The Shape of Water.”

Janney has largely earned recognition for her television work, winning six Emmy Awards for her roles on shows like “Mom” and “The West Wing.” Her films include “The Help,” “The Hours,” and “Juno.”

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