Hayden Panettiere may be best known for playing a cheerleader in US drama Heroes, but she looked a million miles away from being a high school babe last night (February 20th) as she graced an LA event in a glamorous red dress.

Attending the Vanities 20th Anniversary party, the 22-year-old was accompanied by her footballer beau Scotty McKnight, as she wowed onlookers in her chic ensemble.

The star’s full-length gown was paired with sparkling silver heels, a bright yellow clutch handbag and diamond earrings.

It was an uncharacteristic look for Panettiere, who typically sports more funky outfits like shorts, sweaters and trainers, not that those would have been appropriate for the star-studded event.

Last year, the brave actress took on a controversial role in Amanda Knox: Murder on Trial in Italy, which was made for TV.

Hayden stepped into the boots of the elusive murder suspect acquitted of the killing of British student Meredith Kercher, who was recently freed after spending four years in prison for the crime.

21-02-12 1 Panettiere stuns in red gown at LA event