(CNN) -- When actor Jack Nicholson stepped on the Oscar stage Sunday night to announce the nominees for best picture, few expected him to toss to a co-presenter.
"Tonight, it is my great pleasure to introduce live from the White House, the first lady of the United States: Michelle Obama," he said.
Suddenly, the first lady could be seen standing on screen, appearing from the nation's capital in a glamorous silver and black gown. Standing in the background of her cameo, which came about seven minutes before midnight on Eastern Standard Time, was a group of military aides in formal attire.
"I am so honored to help introduce this year's nominees for best picture. And to help celebrate the movies that lift our spirits, broadened our minds and transport us to places we had never imagined," she said. "This has been an exciting year for movies."
"They reminded us that we can overcome any obstacle if we dig deep enough and fight hard enough," she continued. "And find the courage to believe in ourselves. These lessons apply to all of us, no matter who we are, or what we look like, or where we come from or who we love."
She further used the moment to thank those in the room back on the West Coast for contributing to the film industry, arguing they did "vitally important work" and promoted engagement of the arts for young people.
Nicholson then presented the nine titles and gave the spotlight back to the first lady.
"Do you have your envelope?" he asked, looking back up to the screen with Obama
"Not yet, Jack, but I'm about to," she said, as she was handed the gold envelope. "Now for the moment we have all been waiting for: And the Oscar goes to 'Argo'."
Earlier in the night, Obama hosted a dinner with her husband for visiting governors from cross the country at the White House, where she wore the same dress, designed by Indian-American designer Naeem Khan.
In a statement late Sunday night, Kristina Schake, the first lady's communications director, said the Academy Awards had approached the first lady about being a part of the ceremony.
"As a movie lover, she was honored to present the award and celebrate the artists who inspire us all -- especially our young people -- with their passion, skill and imagination," Schake said.
Her surprise appearance was kept secret by the White House--even the press pool assigned to cover the Obamas on Sunday was not told beforehand about the event.
Asked after the show what it was like to hear the first lady announce that "Argo" had won best picture, Ben Affleck--who starred in, produced and directed the film--said it was an honor.
"Honestly, I was just asking these two guys (co-producers George Clooney and Grant Heslov) outside, was that Michelle Obama? The whole thing kind of alarmed me at the time. But in retrospect, the fact that it was the first lady was an enormous honor and the fact that she surrounded herself by service men and women was special and I thought appropriate. Anyway, it was very cool."
George Clooney, another producer of the film, said her appearance signaled good news as they awaited the final award of the night.
"Obviously at certain points we thought that other films might win this," a reporter said at a press conference. "Could you describe when exactly you felt a tipping point in your favor?"
"Michelle Obama," Clooney said.
The moment capped a busy weekend for the first lady. She drew big laughs during her stop at Jimmy Fallon's late-night comedy show Friday when she showed off her moves in a segment with Fallon on "mom dancing."
And the White House announced that Big Bird, the longtime character from public television's "Sesame Street," teamed up with Obama to film two public service announcements that encourage kids to eat healthy and get active. The White House said the PSAs will help mark the third anniversary of the first lady's "Let's Move" campaign, a push "to ensure that all our children grow up healthy and reach their full potential."
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