Lady Gaga performed at the Toronto International Festival during the official premiere of her new documentary Gaga: Five Foot Two on Friday night. Gaga took the stage to give a stunning acoustic performance of her 2009 hit single "Bad Romance" just minutes before the Chris Moukarbel-directed doc made its debut at Toronto's Princess of Wales Theatre.

"It's a difficult thing to let somebody into your life, and I think it happened slowly and organically, and there were points where she could've pulled the plug on it, but she allowed it to happen and then we had a finished film," Moukarbel said of working with Gaga on the documentary, while she added: "It was a challenging time. There were extreme highs and my life has completely changed in the most wonderful way that I would never take back, but it also included the lowest of lows."

Gaga: Five Foot Two hits Netflix on September 22nd. Watch Lady Gaga perform "Bad Romance" at the film's premiere below...