Timman played Ng4

[Event "Hoogovens"]
[Site "Wijk aan Zee"]
[Date "1980.01.31"]
[Round "13"]
[White "Sigurjonsson, Gudmundur"]
[Black "Timman, Jan H"]
[Result "0-1"]
[ECO "B07"]
[WhiteElo "2475"]
[BlackElo "2600"]
[PlyCount "50"]
[EventDate "1980.01.15"]
[EventType "tourn"]
[EventRounds "13"]
[EventCountry "NED"]
[EventCategory "11"]
[SourceTitle "MCD"]
[Source "ChessBase"]
[SourceDate "1999.07.01"]
[SourceVersion "1"]
[SourceVersionDate "1999.07.01"]
[SourceQuality "1"]

1. e4 d6 2. d4 Nf6 3. Nc3 g6 4. Bc4 Bg7 5. Qe2 Nc6 6. e5 Ng4 7. Bb5 O-O 8. Bxc6
bxc6 9. h3 Nh6 10. Nf3 c5 11. dxc5 Bb7 12. Bd2 Nf5 13. O-O-O Bxf3 14. Qxf3 Bxe5
15. h4 Qd7 16. Qh3 h5 17. Rhe1 Bg7 18. c6 Qxc6 19. g4 hxg4 20. Qxg4 Rab8 21.
Rg1 Nd4 22. Rg3 Rb4 23. f4 Rxb2 24. Kxb2 Qb7+ 25. Kc1 f5 0-1