1.d4
Nf6
2.c4
e6
3.Nc3
Bb4
4.e3
0-0
5.Bd3
d5
6.Nf3
b6
7.0-0
Bxc3
8.bxc3
Bb7
9.cxd5
exd5
10.Ne5
Nbd7
11.f4
Ne4
12.Qc2
Nxe5
13.fxe5
Rc8
14.a4
c5
15.Bd2
Qc7
16.Rf3
cxd4
17.exd4
Qe7
18.a5
Rc6
19.axb6
axb6
20.Ra7
Ra8
21.Rxa8+
Bxa8
22.Bxe4
dxe4
23.Qxe4
White's a clean pawn up.
23...Rc8
24.d5?!
[24.Qf5
or; 24.Qg4
attacking the Rc8 gives White time to avoid returning material.]
24...Qc5+!
25.Qd4
Qxd4+
26.cxd4
Bxd5
27.Rc3
Rxc3
28.Bxc3
Now with bishops of opposite colors, the game should be a draw. But White's two center pawns on the same color as his bishop make things a little awkward, so White has a narrow path to walk on here. As we've seen before in Allen's games, he plays a fine endgame to take advantage of some imprecise moves and brings home the win.
28...Kf8
29.g3
Ke7
30.Kf2
Kd7
31.Ke3
Kc6
32.Kd3
Kb5
33.Bd2
Ka4
34.Kc3
b5
35.Kb2
b4
36.Bg5
Kb5
37.Be7
Kc4
38.Bf8
g6
39.Bc5
b3
40.h4
Kd3
41.Bb6
Ke4
42.e6?!
Bxe6
43.Kc3
Kf3
44.Bc7
f6
Allen gets to work creating another passed pawn.
45.Kb2
g5
46.hxg5
fxg5
47.Bd6
h6
48.Kc3
h5
49.Be5
h4
50.gxh4
gxh4
White resigns. 0-1