Celebrity trainer Jillian Michaels entertained A-listers including Leonardo DiCaprio and Jamie Foxx by blowing fireballs at the Darby Downstairs on Friday. We’re told Michaels “was blowing fireballs by lighting shots in her mouth behind the bar,” mesmerizing a crowd that included Jerry Bruckheimer, Cuba Gooding Jr., Mark Sanchez, Jonah Hill and Paul Haggis. Despite the fireballs, nobody missed a “stunning” Cameron Diaz in red cowboy boots chatting with the guys.