[PS 16+1 (18)] I should have folded, but didn't:. Now what?

[FourthWin]

This is not a pat on the back, but two hands that really made me nervous, even given the outcome. But, someone I respect says "Money in NL doesn't come from big pairs, but from cracking them."

Clearly, I got lucky here. So early in the tourney, do you put guys on aces with this action? Fold pf? On the flop? On the turn? Should he have called? This is technically not a stt, but an 18 seat. The action in one of these seems to play a lot like a 9 seat, especially early. I thought he missed on the flop, thought at the turn I might be in trouble, but felt I had to make a play on the river after the check.

Thanks for any input. I know I sucked out, just wanted some input.

I was 1/2 expecting to see KQ from UTG+1, but felt like I had to bet it when he didn't on the river.

PokerStars Tournament, Big Blind is t20 (9 handed) Converter on pregopoker.com

UTG (t1500)
UTG+1 (t760)
Fourthwin (t1500)
MP2 (t1500)
MP3 (t2470)
CO (t1500)
Button (t1490)
SB (t1280)
BB (t1500)

Preflop: Hero is in MP1 with J[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/spade.gif[/img]
<font color="red">UTG raises to t80</font>, <font color="gray">UTG+1 folds</font>, Fourthwin calls t80, <font color="gray">MP2 folds</font>, MP3 calls t80, <font color="gray">CO folds</font>, <font color="gray">Button folds</font>, <font color="gray">SB folds</font>, <font color="gray">BB folds</font>

Flop: (t270) 5[img]/images/graemlins/club.gif[/img] 4[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/diamond.gif[/img] (3 players)
<font color="red">UTG bets t200</font>, Fourthwin calls t200, <font color="gray">MP3 folds</font>

Turn: (t670) 7[img]/images/graemlins/club.gif[/img] (2 players)
<font color="red">UTG bets t400</font>, Fourthwin calls t400

River: (t1470) K[img]/images/graemlins/heart.gif[/img] (2 players)
UTG checks, <font color="red">Fourthwin bets t820 (All-in)</font>, UTG calls t820 (All-in)

Results in gray below:
<font color="#f7f7f7">Fourthwin has Jc, Ks (three of a kind, Kings)</font>
<font color="#f7f7f7">UTG has Ad, Ah (two pair, Aces and Kings)</font>