Playing against an aggressive player 3-handed with >10BBs

I just dumped a 3-handed chip lead at the FT of an MTT. Needless to say, this is embarassing for someone who plays SnGs all day and reads this forum. The payout was 1-1.44-2.25 or 21-31-48. I know that one mistake I made was seeing that second was sweeter than in SnGs and overreacting to that (I didn't bother to calculate the ratio, just eyeballed it and thought it was actually significant).

Anyway, I encountered a totally new obstacle. Blinds were about 3k/6k, and we all fluctuated around 120k, basically even. One player got superaggressive and really frustrated me. The problem in particular that I had is that, at first, I didn't wanna push a 120k stack with 6k blinds covered, and if I didn't push, he often would--or he'd even stop and go, though I'm not sure he intended to before the flop. In a case like this, should I just start pushing with 20 BBs, and what hands should I do it with? Should I raise normally with premium hands to get him to push so I can call, and what should I do that with?

I think my major mistake was overestimating second--maybe I could've even placed second if I wasn't so worried about doing it [img]/images/graemlins/smile.gif[/img]. So, lesson learned, and going to bed unhappy with a substantial win for me.

Advice much appreciated.