7.gxh3? Qg1+! 8.Bxg1 Rxg1+ 9.Kh2 Nf3#

Now White can't save his queen.

Before going e4-e5, White prevents any counterplay with ...Nh5-f4.

Parrying the threat of 2 exd5.

Preparing Rf3, to the concern of the h4-pawn.

4...h3 5.Rxh3 Nxf4 6.Bxf4 Qxf4 7.Rf3 Qg5 8.Rg3+-

Having a sound extra pawn, White went on to win.

White aims to restrict the black knight by g2-g4, and for this idea to work he must first swap a few pieces.

The key move, which leaves the black knight badly placed for the rest of the game.