Jessie tells doctors "Are you c-c-c-razy?"

Jessie J's revealed she defied doctors orders to perform at the Summertime Ball.

Jessie performed her set from a golden throne with her legs in plaster after slipping and injuring herself in rehearsals on Saturday.

The Price Tag star told the crowd, "I only went and fell of the platform and mashed up my foot. The pain is so bad and I was told to stay at home and I said "are you mad, are you cr-cr-cr-crazy I'm not letting my fans down."

Jessie, clearly in pain tried to stand a couple of times during her set which included 'Do It Like a Dude' and 'Who You Are'.

She told her fans - "You have been stupidly fun and thank you for making this the best year of my life."

Jessie - thank you and get better soon.