[Event "Interzonal-04"]
[Site "Portoroz"]
[Date "1958.09.07"]
[Round "20"]
[White "Panno, Oscar"]
[Black "De Greif, Boris"]
[Result "1/2-1/2"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. a3 Bxc3+ 6. bxc3 Qe7 7. Bd3 e5 8. Ne2 d6 9. O-O Nc6 10. Ng3 e4 11. Bc2 Na5 12. f3 Nxc4 13. fxe4 Ng4 14. Qf3 Qf6 15. Bd3 Qh4 16. h3 Nge5 17. dxe5 Nxe5 18. Qf4 Qxf4 19. exf4 Nxd3 20. Be3 Nb2 21. Ra2 Nc4 22. Bc1 1/2-1/2