Power to imagination

Realising that my position (White) is nothing to be proud of, I played Qf4 with the hope to target the only weakness in Black's position: the king. Indeed, most of Black's forces are concentrated on the queenside, and so I was hoping that after

1...Nxb2

I could have won with a very cool queen sacrifice.

2.Qxf7+?!?! Kxf7

3.Be6+ Kf6

4.f4!

White is simply threatening g4-g5 checkmate. My opponent failed to find a solution to this problem (it was a blitz game), and played

4...Qc5+

5.Kh1 Qxc2??

6.g4 g5

7.fxg5+ Kg6

8.Bf7#

Nice! And Yet, Black could have defended. Can you see how?

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The strong and winning defensive move was

5...Qc3!

Now the attack does not work because

6.g4 Qxh3+

7.Kg1 Qxh6!

And the king is safe. For this reason, the queen sacrifice is incorrect (although it was successful), and the best move would have been Re3 instead of Qxf7+, threatening a similar checkmate, Qxf7+-Kxf7, Be6+ Kf6 and Rf3#. However, Black can defend by moving the rook from e8 (for example Reb8) to create an escape square from the king, sigh...