Knock the stuffing out of somebody
Definition 1 of 2
Pro Tip 1/3Physical Confrontation
Often implies a threat or fear of physical violence. 
The boxer boasted he'd knock the stuffing out of his opponent.
Pro Tip 2/3Metaphorical Beatdown
Can be used to describe non-physical defeat, like in games or debates. 
She knocked the stuffing out of them in the chess tournament.
Pro Tip 3/3Overwhelming Victory
Implies a complete or resounding victory over someone else. 
Our team is going to knock the stuffing out of the competition.