Joan Collins was left red-faced on Tuesday night (16JAN07) after accidentally exposing her lingerie during her new play LEGENDS. A broken zip led to a wardrobe malfunction, which caused the actress' dress to slip down during a performance at the Wadsworth theatre in Los Angeles - and left her inadvertently showing off her underwear to stunned fans. The 73-year-old and co-star and former DYNASTY rival Linda Evans desperately tried in vain to zip Collins up, but the actress felt she'd have to break character and explain herself to audience members, which included Hart To Hart stars Robert Wagner and Stefanie Powers and Dynasty's PAMELA SUE MARTIN, among other stars. Evans then had a little fun at her co-star's expense, offering, "Nice butt," as the audience giggled. At the show's after-party Collins said, "I tried, but it just didn't want to stay. "How embarrassing. But I had to make it fun, because if you're not having fun, neither is your audience."