donkey punched

She looked up at me, dazed, as if someone had just donkey-punched her in the back of the head. She grabbed the waistband of my boxers to steady herself. At this point I was confused. Should I help her up or dick-slap her in the face?

2005, Michael Edwards, Adam Steele, Roger Cameron, The Obscene Chronicles, Outstanding! Productions, →ISBN, page 38

His skull snapped forward like he'd been donkey-punched. He'd been shot at point-blank range and expected to find the back of his head blown apart: bone fragments, spattered brains.

2008, Craig Davidson, The Fighter, Soho Press, →ISBN

All right, next one to get donkey punched in the back of the head is second driver.

2011, Michael Oellig, Adventures in a Midwest Purgatory, Xlibris, Corp., →ISBN, page 107

Clark asked Shaw, "Have you ever been donkey punched?" The comment made her uncomfortable because of the accompanying gesture he used and the way he said it. She did not know what he meant at that time and assumed he was referring to a violent act. Shortly thereafter, however, she asked her sister Tara about the term. Tara told her the phrase had a sexual connotation and referred to a sexual position. In a declaration, filed in opposition to the summary adjudication motion, Shaw stated that within a few days of Clark's comment, Tara explained to her that "donkey punched" described an act of anal sex by tackle or force, involving violence.

2011 February 22, Judge Kriegler, “Undisputed Facts in the Summary Adjudication Motion”, in Shaw v. Longs Drug Stores California Inc., Court of Appeal of California, Second Appellate District, Division Five