[Event "Interzonal-09b"]
[Site "Petropolis"]
[Date "1973.08.15"]
[Round "16"]
[White "Portisch, Lajos"]
[Black "Bronstein, David Ionovich"]
[Result "1/2-1/2"]

1. d4 d5 2. c4 c6 3. cxd5 cxd5 4. Nc3 Nf6 5. Nf3 Nc6 6. Bf4 Bf5 7. e3 e6 8. Bd3 Bxd3 9. Qxd3 Bd6 10. Bxd6 Qxd6 11. O-O O-O 12. Rac1 Rac8 1/2-1/2