World champ gets crushed in World Cup play!!

.​[Event "Tbilisi FIDE World Cup"]
[Site "chess24.com"]
[Date "2017.09.09"]
[Round "18.1"]
[White "Carlsen, Magnus"]
[Black "Bu, Xiangzhi"]
[Result "0-1"]
[ECO "C55"]
[WhiteElo "2827"]
[BlackElo "2714"]
[Annotator "Vas Sladek"]
[PlyCount "72"]
[EventDate "2017.??.??"]
[WhiteTeam "Norway"]
[BlackTeam "China"]
[WhiteTeamCountry "NOR"]
[BlackTeamCountry "CHN"]
1. e4 e5 2. Bc4 Nf6 3. d3 Nc6 4. Nf3 Be7 5. O-O O-O 6. Bb3 d6 7. c3 Be6 8. Re1
Qd7 9. Nbd2 Rab8 10. Bc2 d5 11. h3 h6 12. exd5 Nxd5 13. Nxe5 Nxe5 14. Rxe5 Bd6
15. Re1 Bxh3! {A beautiful piece sacrifice against the best player on the
planet!} 16. gxh3 Qxh3 17. Nf1 {Of course, there was no direct mate. But
consider Black's compensation: the White King has no cover, black advances his
king side pawns, White's rook on a1 never gets out and White has to return the
extra piece. Best of all, Black has all the fun and play!} Rbe8 18. d4 f5 19.
Bb3 c6 20. f4 Kh7 21. Bxd5 cxd5 22. Re3 Rxe3 23. Bxe3 g5 24. Kf2 gxf4 25. Qf3 {
White has to return the piece. If he plays something like 25.Bd2?! then Rg8-+ and
it will get ugly for White.}
25... fxe3+ 26. Nxe3 Qh2+ 27.
Kf1 Rg8 28. Qxf5+ Rg6 29. Ke1 h5 30. Kd1 Kh6 31. Nc2 h4 32. Ne1 h3 33. Nf3 Qg2
34. Ne1 Qg4+ 35. Qxg4 Rxg4 36. Nf3 Rg1+ (36... Rg1+ 37. Nxg1 h2 38. Kc2 h1=Q
-+) 0-1