another check raise deep with an overpair

[LAgambol]

10/20 NL
villain was pretty aggro young player, who had been winning so far. i saw him about a little later on some TV poker broadcast and he seemed to be at least semi-well known TV pro, hadn't seen or played with him prior tho
Hero was playing super LAG and had been running over the table, tripling my stack in the first couple hours
villain has 4K, Hero covers

Hero has KK
villain in MP makes it 100, one caller, hero in BB makes it 350, villain calls

Flop:
8 4 2
Hero bets 500, villain calls

Turn: Q
hero checks, villain bets 800, Hero raises to 2500, villain goes all in, hero calls