Okay, I've watched this episode twice and I'm still really puzzled by this scene.

So did Daphne know that Knox was coming after her to make sure she did the job? And if so, when Knox was listening at the door, was he already hallucinating their conversation? If so, then this was seriously effective and miraculously played out pre-emtive strike on Matt's part. If Knox was playing into Matts hands the whole time, how did Knox get powered up? Was that an illusion too?

This is a pointless thread, I realize, but I'm having a little trouble putting this scene together in my mind.

Well, I think it's clear that Matt can control pretty much any aspect of the brain. So I'm guessing he heard Knox coming by hearing him telepathically. You usually think before you barge into a room to do something. I'm guessing Matt also gave Knox his feeling of strength. He put the fear in his head. I'd imagine that Matt has a LOT of control over his power to do that though.