Beyonce Knowles shocked fans at a performance last week (15Aug07) when she accidentally bared her breasts on stage. The Naughty Girl was appearing at the launch of her clothing line Dereon in Toronto, Canada, when the mishap occurred - but footage of the exposure has been posted on the internet. During an energetic dance routine, Knowles' top lifted up, revealing her bare breasts to hundreds of fans. It is the latest on camera - and on-stage - embarrassment for the singer. Last month (Jul07), footage of Knowles taking a tumble at a gig in Florida was uploaded on video-sharing site YouTube, despite pleas from the singer for fans to keep the incident private.