The boyband was performing at the Scottish Exhibition and Conference Centre in Glasgow on Tuesday (26Feb13) when Styles picked up a piece of footwear that had been thrown onto the stage.
As he held it up, another over-enthusiastic devotee hurled her shoe at the singer - inadvertently smacking him in his crotch and causing him to fall to the floor as bandmate Liam Payne quipped, "Well, he has just been assaulted!"
One Direction fan Jade Anderson has now come forward and owned up to the mishap, admitting she feels horrible for hurting the pop hunk.
She tells Scotland's Daily Record newspaper, "I just wanted him to touch something belonging to me. I didn't mean to hit him where I hit him, I'm really embarrassed."