Did I Misplay This - Final 4, $50+5, $50,000 Guarantee Bodog Tourney

[imago]

We're down to four players, out of 711, when the following hand came up.

I am the BB and chip leader with 824K, UTG has 306K, BTN has 420K and SB has 583K. Blinds are 20K/40K, 4K antes.
Pot is 76K pre-flop.

UTG: folds
BTN: calls
SB: completes blind
BB: checks with A [img]/images/graemlins/spade.gif[/img] - 2 [img]/images/graemlins/diamond.gif[/img]

Pot is 136K

Flop: A [img]/images/graemlins/club.gif[/img], J [img]/images/graemlins/spade.gif[/img], J [img]/images/graemlins/heart.gif[/img]

My thinking: This pot is mine! Neither of the other players in the hand has shown any strength. I have flopped top two pair. My kicker is irrelevent. Only four cards can hurt me and it's almost 11 to 1 against either of my opponents having one of them. I'm taking this pot now!!

SB: checks
BB: bets 454K
UTG: all-in with 420K
SB: calls

Pot is 1.464M

Turn: 7 [img]/images/graemlins/club.gif[/img]

SB: all-in with remaining 129K
BB: calls

Pot is 1.722M

BTN: shows A [img]/images/graemlins/diamond.gif[/img] - 8 [img]/images/graemlins/diamond.gif[/img]
SB: shows J [img]/images/graemlins/club.gif[/img] - 9 [img]/images/graemlins/club.gif[/img]
BB: shows A [img]/images/graemlins/spade.gif[/img] - 2 [img]/images/graemlins/diamond.gif[/img]

River: 3 [img]/images/graemlins/heart.gif[/img]

Ouch!!! How could I have averted this - could I have averted this?

Should I have raised pre-flop?
Should I have made a more modest bet on the flop or checked it?
Should I have folded when the SB put his remaining chips in?
I would have still had 306K if I had.

What would any of you have done differently?

I had played a really beautiful tournament to that point.

Thanks,
imago