[Event "It (open) \"] [Site "masterchessopen.com Cologne (Germany)"] [Round "0"] [White "Buttner K"] [Black "Chwallek B"] [Result "1-0"] [ECO "B33"] [Opening "Sicilian: Open, 2...Nc6"] 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 d6 6.Bg5 e6 7.Qd2 a6 8.O-O-O Bd7 9.Be3 Rc8 10.h3 Na5 11.g4 h6 12.f4 Nc4 13.Bxc4 Rxc4 14.g5 hxg5 15.fxg5 Nh5 16.Rhf1 Qc7 17.Qf2 Bc8 18.Nb3 Rc6 19.Kb1 b5 20.Nd5 exd5 21.exd5 Rxc2 22.Qxc2 Qxc2+ 23.Kxc2 Bxh3 24.Rfe1 Be7 25.Nd4 O-O 26.Rh1 Bg4 27.Rdg1 f5 28.Rxg4 {#r} 1-0