I ran into what i thought was some pretty sick spots on day 1 of the main, i labeled this Part 1 so we dont have multiple hands being discussed at once.  When i first sat down at my table i only recognized 1 person at my table who was Alex Queen.  We played together a decent amount, very solid player but not someone i would try to avoid.  To start the tournament the first hand off the deck i got 88 in the BB, MP opens im the only caller, flop is T85r, turn K, river 2.....MP had flopped a set of Tens....cool story, what a dreamy start to the WSOP Main Event.  Down to 16k already but im not discouraged at all.  But the hand i want to talk about happened in level 3 at 150/300, i chipped up to about 28k.

I open UTG to 700 @ 150/300 with 28k, I have AdQs

Folds to the BTN, he 3b to 1600. My perception of this guy is that hes a nit, older guy in his 40s, hasnt 3b yet.  

I call and were HU, this is probably a fold IMO against the villain.

Flop is K73ddd, i have the Ad. I check, he checks back rather fast.  

Turn is Qh, i lead for 2.4k, he thinks for about 5 seconds and calls

River is Qc, I check with intentions on check calling, He takes his time and leads out for 9k. 

IMO most players are just snap calling and just shrug there shoulders if they lose, it took me maybe 4 min, but i found a fold.

My thought process here was what hands does he check the flop after 3b the btn, I have the Ad so i really doubt that he could have flopped a flush with his 3b range, and if he did it would have to be Q high so he would want to bet cause i have a lot of Aces in my range to call a 3b OOP.  

With that being said, what can he check the flop but call the turn with on a all Diamond board?  Maybe a set of KK or 77 IMO, and hes just trying to exercise pot control?  Once the river comes and it pairs the board and i have trip Q with a A kicker im suppose to like my hand a lot here but i feel like my hand got worse.  I checked rather quickly, and he bets pretty big.  I didnt understand why he bet so big unless he thought i flopped a flush or maybe i have something like JdJx or AdKx, AdQx.  Seemed like he knew i had a very strong hand from my bet on the turn, i think he expects to get payed off by all flopped flushed, and AK, AQ.  This hand has been bothering me since sunday, what do you guys think?