I suggest that he receive a stunning blow - say, to the back of the neck?

His thoughts were driven away by a stunning blow to the side of the head.

The leopard knew that something was wrong when it felt a stunning blow on its head.

The attack came from behind the fence, they thought, and began with a stunning blow on their heads.

It was as though he had received a stunning blow.

At the same time, a failure could be seen as a stunning blow to global trade talks.

The decision, after four months of speculation, was a stunning blow to state Republican leaders.

That stunning blow was too much, even for Spanish soldiers.

The defeat of the resolution was a stunning political blow as well.

Then he was smashed down by a stunning blow to the back of his head.