US President Barack Obama bows to First Lady Michelle Obama at the Inaugural ball in Washington, January 21, 2013.(Agencies)

Click for more photos of the Inaugural ball

Michelle Obama made a daring decision to return to the same designer who created her Inaugural Ball dress four years ago - and the risk paid off.

The First Lady looked stunning in a sweeping, velvet and chiffon, ruby-colored dress by designer Jason Wu. She teamed the dramatic gown with heels by Jimmy Choo and a diamond ring by Kimberly McDonald.

She surprised the fashion establishment by returning to a Wu design which had been custom-made for her.

Four years ago at her first Inauguration Ball, Michelle shimmered in an off-white, one-shouldered floor-length couture gown by the designer.

Wu, who was 26 at the time and had only been working in fashion for three years, saw his career take off after the First Lady's surprise decision to wear one of his dresses.

He said at the time that he was unaware she had chosen the gown and had been watching at home on his couch and eating pizza when she appeared.

After her 2013 decision, Wu told Women's Wear Daily: 'Mrs Obama likes to keep her secrets. She fooled me again.'

Wu released a women's clothing and accessories collection at Target last year and continues to be popular with the First Lady for official engagements.

The sleeveless, cross-halterneck dress with low-cut back flattered 49-year-old Michelle's toned arms and neat waist.

It had been created especially for her by Wu and was a departure from the somber palette she stuck to at earlier inauguration events.

Mrs Obama's new hairstyle - she had bangs cut in on her birthday last week - had been loosely tousled for the special night.

Vice-President Joe Biden's wife Jill also looked glamorous in a blue silk dress by Vera Wang at the Inauguration Ball.