This is a game from a local tournament, played yesterday. I won this game, but I'm not quite sure why I won. Please help me walk through this game and figure out what went right.

i think its because he was about to lose a queen

Although Qxc5 was still a good move, your opponent responded badly to it. After 30... Qxc5! 31. dxc5 Nf4+ 32. Qxf4 gxf4 33. gxf4 you are up the exchange, but down a pawn, which is a very hard endgame to win, especially under time pressure. But I think you still would have had a clear advantage because of his tripled f pawns.

I was anticipating that very exchange, and the tripled f-pawns would have been great for me, and I believe I could have picked up the b-pawn, should anything go amiss. Of course, I was fairly confident, because I'm a pretty fast player, and I had a three-four minute advantage over my opponent.

The move didn't even occur to me until after he moved 30.e4. It would have been great if I had noticed it earlier, because it may have saved some time. As it is, I'm ecstatic over the very discovery, and the long wait between moves... the slightly confused look on my opponents face, followed by the knowledge of what had just happened dawning on him. That, along with a decent 3-5 minute wait for a move, made me feel like I wasn't a beginner.

Thank you, everyone, for posting!

Nice game, though I still have trouble with these 3d pieces.

Hmm... I had no idea it would be harder for people to see with the 3-d pieces... I'll keep that in mind, thanks.

EDIT: Is this any better?

Nice tactical find! I agree with Tony though, I think Nf4+ would've been better. It's always good to look at one tactic with different move orders.

I would not have resigned had I been him however. It is a tough win for black after 37.Qc4. Black should still win of course but it would take a significant amount of time and thought with 2R v R+B.

On move 15...Bxf3  that was a great move, but you would've ended up a piece.  White's response was the best. 

 Move 19...a5 was not really a pointless move. You had a threat of attacking the bishop, since that was your original plan when you used  your knight to attack it. But I think the move gave you a slight spatial advantage. 

 On 21. hxg3 did you figure 21. fxg3?  That would've been better for white.  chess is played on the entire board, so whatever positioning of your pieces that can give you an advantage you have to create and/or find throughout the board.  As a rule of thumb pawns are stronger horizontally than vertically, with some exceptions.

I think 25... g6 is fine.

26. Kg2  Actually I think 26.e4 would hurt you.  you never really defended against that move, but white didn't play it in time.

Finally, 30.. Qxc5 was a great find.  I think that really decided the game being an exchange up.

To me, it seems like White's total play suffered from "tunnel vision".  He seemed fixed on one idea (i.e. play on the c-file), and you stopped his plans of attack rather easily.  Very nice job!!

Well, he had three mintues left on his clock, and I had between 7 and 8. My opponent is notorious for hosting tournaments with a time control of 150 minutes per player per game. He is not suited for any form of Blitzing, so he just saved me the trouble of having to continue.

knight normally goes to d7 in the QGD tartacower variation

Well, checkmateisnear, I haven't studied any true Queen's Gambit lines (I play the KID or Grunfeld). I was expecting him to play a King's Indain Attack, so I followed my opening and continued with the French, knowing it is acceptable and somewhat irritating to KIA players.

I can understand checkmateisnear's comment, but in the game in question, IMO I think ...Nc6 was playable, meaning that the move doesn't diminish black's play for the center too severely.  I mean, I can see why ...Nbd7 is strong in this position, but I wouldn't object to this move.