1. d2d4 "I pretty much spent the whole night looking at 1.e4..." (Nakamura)  1... f7f5 What else in a must-win situation?! 2. g1f3  2... g8f6  3. c2c4  3... g7g6  4. g2g3  4... f8g7  5. f1g2  5... e8g8  6. e1g1  6... d7d6  7. b1c3  7... b8c6  8. d4d5  8... c6a5  9. b2b3  9... c7c5  10. c1b2  10... a7a6  11. f3g5  11... a8b8  12. d1d3  12... d8e8  13. c3d1  13... b7b5 A glance at the position reveals that Black can be happy with  his opening choice. Not because he has the advantage; in fact Nakamura  thought that White is better. What is important here is that not a single  pawn has been traded yet and the tension is all over the place. An  important thing is that Nakamura has a lot of experience in the arising  positions, whereas Xiong plays 1.d4 less frequently. 14. d3d2  14... a5b7 This  knight might be a problem sometimes in the arising pawn structure but in  comparison to the KID Black has the f7 square available for it. 15. d1e3  15... b7d8  16. g5h3 A novelty. 16... c8d7  17. a1d1 Xiong solidified the center. 17... b5b4 However Nakamura fixed a potential weakness on the queenside. 18. d2c2  18... a6a5  19. h3f4  19... a5a4  20. h2h4  20... b8a8  21. c2b1  21... a8a6 Black's play is definitely easier. He is  threatening to open the a-file in a good moment, but may also play on the  kingside. At the same time it is difficult to say what does White do  concretely. 22. g2f3  22... e8f7  23. e3g2 "I am sure that White is fine (after  this move), but the the tides are turning very quickly." (Nakamura) 23... f6g4 Taking the good opportunity to secure some nice squares  for his pieces. White's dark-squared bishop is extremely important for the stability of the flank, but now it has to leave. 24. f3g4  24... f5g4  25. e2e4 In search for counterplay while e4-e5 is also on the  agenda. 25... g7b2  26. b1b2  26... f7g7 Now the a-file is secured for the  black major pieces. 27. b2g7  27... g8g7  28. e4e5 Just in time. Otherwise  Black will transfer his knight there, and maybe even further to f3. 28... d7f5  29. e5d6  29... e7d6  30. f1e1 Xiong also got a file for his rooks. 30... d8f7 Avoids the trap. 31. e1e7  31... g7f6  32. e7b7 White searches for counterplay on the queenside. 32... a4b3  33. a2b3  33... f8a8  34. g2e3  34... a6a1 What have started with the move b5-b4! reached its logical finish. Black breaks through the open a-file  and gets closer to the title. 35. g1f1  35... f7e5 This complicates the win. 36. d1a1  36... a8a1  37. f1e2  37... e5f3  38. e3f5  38... f6f5 The black king is ready for a deadly visit. 39. e2e3 The only move. 39... a1e1  40. e3d3  40... f3e5  41. d3d2  41... e1a1 It seems as Xiong will through in  the towel in any moment, but he shows his usual tactical creativity and  gives Nakamura a run for his money. 42. f4e6 White can also create threats! 42... h7h6 Securing the g5 square. 43. b7b6  43... a1a3  44. d2c2  44... a3a2  45. c2d1  45... e5d3  46. b6d6  46... d3f2  47. d1e1  47... f2d3  48. e1d1  48... f5e4 Just one more move and the black pieces will be  united with Ke4-e3 and mate will be inevitable. 49. e6c7  49... d3f2 