Yeah, always look at the back rank....
Don't Get Too Cocky!!!

At 28, Nd3+ looks really strong. There's probably a forced mate in there somewhere that I'm not seeing, but 29. Kf1 Qh1+, 30. Ke2 Nd4+ wins the exchange and eliminates the possibiliy of back rank mate.
What was the time control?

At 28, Nd3+ looks really strong. There's probably a forced mate in there somewhere that I'm not seeing, but 29. Kf1 Qh1+, 30. Ke2 Nd4+ wins the exchange and eliminates the possibiliy of back rank mate.
What was the time control?
3 minutes, although I don't think we were in time trouble. I just was so confident of a mate, that I didn't bother to give it a second though, but your line does indeed lead to the loss of the White queen, and victory.
I thought I had this game bagged, until I was proven otherwise...