[Event "Interzonal-09b"]
[Site "Petropolis"]
[Date "1973.07.30"]
[Round "6"]
[White "Ivkov, Borislav"]
[Black "Panno, Oscar"]
[Result "1/2-1/2"]

1. Nf3 c5 2. c4 g6 3. d4 Bg7 4. d5 d6 5. e4 Nf6 6. Nc3 O-O 7. Be2 e5 8. Bg5 h6 9. Bh4 Qc7 10. Nd2 Nh7 11. a3 Bf6 12. Bxf6 Nxf6 13. h4 h5 14. f3 Kg7 15. Nf1 Qe7 16. Ne3 Na6 17. Qd2 Rb8 18. b3 1/2-1/2