International Pop superstar Lady Gaga got the 2010 Lollapalooza crowd hype Friday night (Aug 6) as she took to the main stage and performed her entire “Monster Ball” concert set during Day 1 of the annual music festival, held at Grant Park in Chicago, IL.

Just hours before she was set to close out the first night of the Lollapalooza Music Festival, the always unpredictable Lady Gaga, wearing a tattered fishnet bodysuit and gold star pasties to cover up her nipples, made a surprise appearance on-stage during Semi Precious Weapons‘ set and later jumped into the crowd for some old school crowd surfing amongst her “little monsters!”

Check out 15+ pictures of Gaga rocking out at Lollapalooza 2010 at Chicago’s Grant Park below and continue reading for video footage of her crowd-surfing with Semi Precious Weapons…