chip leader in a $55 Party rebuy, confusing top pair hand

[billyjex]

hey guys,

this just happened in a Party $55 rebuy. 40 left out of 120, I'm chip leader w/ 16k. Main villian in this hand has 12k. I haven't really been paying attention to him and have no read (he hasn't been at my table long.) Blinds are 150/300.

I am dealt KJo in MP2. Folded to me, I raise to 800. Villian calls on the SB.

Two to the flop of 1900. Flop is K 4 2r.

He checks, I bet 1200. He calls.

Turn is a Q. What is my action and how should I proceed in the rest of the hand?