Hayden Panettiere discovered cham pagne, cobblestones and high-heels don't mix during a night out in Hollywood on Thursday. The actress, who is dating heavyweight boxer Wladimir Klitschko, was among the stars to attend a Christian Dior pre-Oscars soiree held at the exclusive Chateau Marmont. But the night almost ended in disaster for the former Heroes star. She tripped Heroes star. She tripped up in her heels as she made her way down the steep cobblestone drive at the famed hotel.Thankfully, there was a rather burly man on hand to catch her and she was able to laugh off the stumble as he helped to steady her helped to steady her back on her feet. The 21-year-old, who plays the lead role in the controversial new made-for-TV movie: Amanda Knox: Murder On Trial in Italy, had earlier turned heads for all the right reasons as she arrived dressed in a bright fuchsia mini-dress and black blazer.