J.Lo wowed by On The Floor dance sequence at shopping mall

Jennifer Lopez was left speechless during a taped TV appearance at The Grove in Los Angeles on Thursday night (03Mar11) - when a group of dancers suddenly performed in sync to her new single.

The singer/actress and American Idol judge was finishing off an interview for news show Extra in front of thousands of fans when her new song On the Floor was blasted out over the shopping mall's speaker system and hundreds of 'flashmob' fans copied her moves from the video.

It was a stunt set up by Extra producers to wow Lopez, who could not believe what she was seeing.

After standing agape at the dance sequence, Lopez regained her composure and said, "Oh my God! That's so crazy! I've got goose pimples all over my body! I love you guys, that was so awesome!"

The TV segment aired in America on Friday (04Mar11).