Surprise, surprise

Proving that you can play almost anything in the opening today, Shakhriyar Mamedyarov caught Alexander Grischuk with a bizarre opening idea in the Ruy Lopez. I don't think I've ever seen g5 played so early by Black in this opening, although the actual move was first played in 1968 (by Portisch against Korchnoi).
There does not seem to be too much subtlety to the move btw, as Mamedyarov used the g pawn to push the knight of f3 before running his h pawn up the board as well. The whole game had a kind of 'coffee house hack' vibe to it, but I am sure I'm doing both players a disservice by describing it like that.

Grischuk,Alexander (2785) - Mamedyarov,Shakhriyar (2791) [C72]
21st European Teams Hersonissos GRE (8.1), 05.11.2017

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. O-O Bd7 6. Re1 g5 7. Bxc6 bxc6 8. d4 g4 9. Nfd2 exd4 10. Nb3 Ne7 11. Nxd4 Bg7 12. Nc3 O-O 13. Bg5 f6 14. Be3 Qe8 15. Qd3 Qf7 16. Qd2 Qg6 17. Bf4 h5 18. b4 h4 19. a4 Qh5 20. Be3 h3 21. Nce2 hxg2 22. Nf4 Qh7 23. Nfe6 Bxe6 24. Nxe6 Ng6 25. Nxf8 Rxf8 26. Bf4 f5 27. exf5 Nh4 28. Ra3 Qxf5 29. Bg5 Nf3+ 30. Rxf3 gxf3 31. Bh6 Qd5 32. Qc1 Bc3 33. Re3 Bd4 34. Rd3 Re8 35. c3 Bxf2+ 36. Kxf2 Re2+ 0-1