By SAMANTHA CRITCHELLForget glamour girls Jessica Chastain versus Jennifer Lawrence. By the end of a long Oscars telecast, the only person who could have stolen the fashion conversation was first lady Michelle Obama â¿¿ and she did. She presented the best picture award almost at the stroke of midnight Sunday via video stream in a silver Naeem Khan gown. It was the sort of Cinderella style moment that red-carpet watchers hunger for. Until then, the most heated chatter about the Academy Awards likely was the boldface battle between Giorgio Armani and Dior Haute Couture. Armani could claim some big wins: the designer dressed Chastain, Naomi Watts and Quvenzhane Wallis. Dior dressed Lawrence and Charlize Theron â¿¿ both are spokesmodels â¿¿ who hit it right in white. Chastain, in a glistening copper-tone strapless gown with mermaid hem, looked like an old-world glamorous movie star, especially with her oversized vintage Harry Winston diamond earrings and bright red lipstick. "I chose it because to me it was a throwback to old Hollywood," she said. "It's a very 'Happy birthday, Mr. President' dress." Watts wore a gunmetal beaded gown with a geometric cutout on the bodice, also by Armani. Quvenzhane (kwuh-VEHN'-juh-nay), with a silver headband in her hair and carrying a bedazzled puppy purse, wore an Armani Junior navy-blue dress with black, navy and silver jewels scattered on the skirt and a big bow on the back. She had another Armani dress, a pink one, ready for the afterparty. "I liked it because it was sparkly and puffy." Lawrence was the belle of the ball in a white-and-pale pink strapless gown with fitted bustier and poufy hemline, sophisticated pulled-back hair, diamond-ball earrings and a delicate long necklace that hung down in back. The long train gave her trouble as she went to accept her award for best actress. She stumbled as she approached the stage to accept her Oscar.