I like Larsen's Opening. I tend to get myself in trouble with it, though.

This already looks good for White. 5...dxc4 feels very strange to me; Black spent his first four moves presenting a strong center, and then immediately gives it up?

9.h3 doesn't appear to serve a purpose. There's nothing really to guard g4 against. I think White would have been better served by 9.d3.

15.e4 *must* be inaccurate. The d3 pawn is now backwards on a half-open file with a bind on d4--Black should be able to win the d-pawn easily. But then 16...fxe4? allows White to dodge the bullet instead.

Now it's Black with the weak backwards pawn, though White may have trouble putting pressure on it immediately.

19...Nd4! What a great spot for the Knight, and if White removes it (as here), Black responds 20...cxd4, converting his weak c-pawn to a strong passer while totally shutting down White's DSB. Very nice!

You've both played this last sequence pretty accurately by my reckoning, though 24.Kh2 is a bit mysterious to me.

I agree: Black is playing especially well in the last few moves. White would probably like to get in f2-f4 at some point, but Black has stymied that pretty much. Probably the WK ought to have gone to h1 instead of h2, at that.

25...d3 Noooo! Black has no chance of promoting yet, or accomplishing anything with this pawn at the moment. It should have stayed on d4 for a while! Now White's DSB is back in the game, and Black's strong centralized pawns become weaknesses to be picked off! I think 25...Bxh3!? had to be considered. It looks like it wins a pawn--if White captures, 26.gxh3 Qh6! appears to be simply winning for Black. And if White doesn't capture, then ...Qh6 might follow next turn anyway!

One of those occasions of a good move played too soon. I would have been tempted to try 25...Qd7 with two possible threats: ...Bxh3; and the positional exchange sacrifice by ...Rc3. The reason 25...Rc3 don't work at once was 26.Bxc3 bxc3 27.Rxc3 dxc3?? 28.Qxd6. The suggestion of bwaa looks even better and more straightforward, too.

Black is desperate. He may as well have resigned after 28...Rf2.

Actually, no: It seems that White can safely ignore them in favour of his own powerful attack: 30.Qd8ch! with the following: [A] 30...Rf8 31.Bc4ch Qf7 32.Bxf7ch Kxf7 33.Qxf8ch Kxf8 34.Rd8ch ... 35.Rxc8 with a 'won' game; [B] 30...Kf7 31.Bc4ch Be6 32.Rd7#; [C] 30...Kf7 31.Bc4ch Qe6 32.Rd7ch Bxd7 33.Qxd7ch etc. In these lines, Black's attack no only doesn't get rolling; it gets decimated.

White can also play Bc4+ immediately and then just play Qxf2 next, winning the R.

Very nice. You'll be up a full two Bishops after this, I think.

Although this counterattack has lost much of its sting, absent the rook on d1, it's still good enough for the win.

It's mate in one! Well played by both of you; it's too bad about Black's blunders from move 25 on; this could have gone on quite a bit longer I think.

Black certainly had his chances, but blew them pretty much with one overhasty move. Good comeback by White, even though missing an even more devastating riposte at move 30.