[Site "masterchessopen.com Varna (Bulgaria)"] [Date "1965.04.07"] [Round "6"] [White "Spiridonov Nikola (BUL)"] [Black "Piskov Kamen"] [Result "1-0"] [WhiteElo "2239"] [ECO "A43"] [Opening "Old Benoni"] 1.d4 c5 2.Nf3 cxd4 3.Nxd4 Nc6 4.e4 g6 5.Nc3 Bg7 6.Be3 d6 7.Bc4 Nf6 8.f3 Bd7 9.Qd2 Qa5 10.O-O-O O-O 11.Bb3 Rfc8 12.Kb1 Ne5 13.Bg5 Qd8 14.Qe2 a6 15.f4 Nc6 16.e5 Nxd4 17.Rxd4 Ne8 18.Nd5 Kh8 19.Nxe7 Qb6 20.Qd2 Rc5 21.Bxf7 dxe5 22.Rxd7 exf4 23.Bb3 Rxg5 24.Nd5 Rxd5 25.Qxd5 Nf6 26.Qxb7 Qxb7 27.Rxb7 g5 28.Re1 g4 29.Ree7 Rd8 30.a3 {#r} 1-0