During a group performance at the city's Verizon Center, Criss bent down to shake the hand of a female fan in the crowd - but he was pulled off the stage by the gig-goer.
The star was uninjured in the fall and remained a true professional by dusting himself off and returning to the stage.
In a series of posts on his Twitter.com page, he writes, "To the lady who pulled me off the stage and into the pit... if I ever see you on a stage... keep your wits about ya (sic).
"Btw (by the way) I'm lucky I didn't hit my head on the gate in front of this lady. Seriously close call... Like, please don't kill me. I'm nice."