[Event "IBM"]
[Site "Amsterdam"]
[Date "1967.??.??"]
[Round "3"]
[White "Portisch, Lajos"]
[Black "Zuidema, Coenraad"]
[Result "1-0"]
[WhiteElo ""]
[BlackElo ""]
[ECO "D55"]

1.c4 Nf6 2.Nc3 e6 3.Nf3 d5 4.d4 Be7 5.Bg5 O-O 6.e3 b6 7.cxd5 Nxd5 8.Bxe7 Qxe7
9.Nxd5 exd5 10.Rc1 Be6 11.Bd3 Rc8 12.O-O c5 13.e4 Nd7 14.Re1 Qd8 15.exd5 Bxd5
16.Bf5 g6 17.Bh3 Rc7 18.dxc5 Rxc5 19.Rxc5 Nxc5 20.b4 Ne6 21.Bxe6 Bxe6 22.Qa1 Qd5
23.a3 a5 24.bxa5 Qxa5 25.Re3 Rc8 26.h4 Bd5 27.h5 Bxf3 28.h6 f6 29.Rxf3 Qg5
30.Qxf6 Qc1+ 31.Kh2 Qxh6+ 32.Kg3 Rf8 33.Qxf8+ Qxf8 34.Rxf8+ Kxf8 35.Kf4 Kf7
36.Ke5 Ke7 37.f3 h6 38.a4 h5 39.f4 h4 40.f5  1-0

