Here's the moment of South Africa's alleged ball tampering

South Africa were rolling along today, continuing to dominate Pakistan in the second Test between the sides in the UAE, when the Proteas were suddenly hit with a five-run penalty for alleged ball tampering.

It appeared as if South Africa's Faf du Plessis was rubbing the ball against the zipper on his panths.

Here's a capture of the apparent rules infraction:

Hard to say what kind of effect that action would have, but that does look pretty clearly like zipper meeting ball.

Update: AB de Villiers, following the match, denying any wrongdoing by his side.