After 4.Bd3, there are many ways to avoid mate, one of which being 4... Bg7.
7 move beauty (queen sac)
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Also 4...Nh6 (which is probably better as it puts the knight in a better position). I'll edit out the 'forced'.
This one is a beauty for white. Good job. You should post this one in the "Post your best miniatures here" thread (Wins in 20 moves or less)...
http://www.chess.com/forum/view/game-showcase/post-your-best-miniatures-here?lc=1#last_comment
Against a 1300+ player. Must have been drunk or something.