$10 SNG.. need criticism

[Patton4]

First time poster who has been learning poker for about the last 5 months is playing a $10 PS SNG. Blinds are 50 100. I'm chip leader with $3600 at the table playing pretty conservatively amongst some aggressive play. I'm the BB and am dealt Ah 10d.

2nd in chips (a player who has called many of my big bets both pre-flop and flop only to fold on the turn) in middle position limps as does the button. I make it 500 to go. 2nd in chips calls, button folds.

Flop comes 8s 4c 10s. I open with my top pair for 1000 not fearing my opponent to have a pp or he would have raised pre-flop. He calls, so I think flush draw. Turn comes 8c. If he's still on his flush draw, I'm gonna make him pay with my two pair, I push all-in. Bad decision???? Results to follow... what did he have?