1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.0-0 Nxe4 5.d4 Nd6 6.Bxc6 dxc6 7.dxe5 Nf5 8.Qxd8+ Kxd8 9.Nc3 Ne7 10.Ne4 Ng6 11.b3 Ke8 12.Bb2 The so-called "Berlin Wall" Variation - which thanks to Kramnik's efforts became fashionable at the top level after his 2000 World Championship match versus Garry Kasparov.
12...c5 A new move.
13.Nfd2! A very strong plan. White prepares to use his kingside pawn majority by advancing the f-pawn. At some moment Black will have to keep the blockade on f5 and therefore Nisipeanu transfers the knight to e3.
13...h5 "I don't like this move at all" (Nisipeanu)
14.Nc4 [14.f4 Bf5 followed by h5-h4 Black keeps the blockade on f5.]
14...b6 [Now after 14...Bf5 the Romanian GM wanted to play the very strong 15.f3! followed by Nc4-e3.]
15...Ne7 "I think this is the only move", commented Nisipeanu after the game. On the other hand this looks pretty ugly for Black and perhaps already here Ivanchuk should have tried to change the character of the position. [Both 15...Bf5 16.Ng3 Bxc2 17.f5 Ne7 with the idea to answer 18.Rf2 with 18...h4! ; and 15...Nh4 16.Ng3 Nf5 17.Nxf5 Bxf5 18.Ne3 Be4 19.f5 Rd8 were preferable.]
16.Ne3 [16.Ncd6+ cxd6 17.Nxd6+ Kd7 18.Nxf7 Rg8 19.f5 was attractive, but Nisipeanu was right that it is far from clear. For instance: 19...Nc6 20.e6+ Kc7 21.Rad1 Be7 ]
16...Nf5 17.Nd5 Bb7 18.Rfd1 Bxd5 19.Rxd5 a5 20.Re1 White threatens a check on f6. Black is in deep troubles.
20...Rd8 [20...Rh6 21.Nf6+ gxf6 (21...Ke7 22.Ng8+ ) 22.exf6+ Ne7 23.Rde5 Rxf6 24.Rxe7+ Bxe7 25.Bxf6 wins]
21.Nf6+ Ke7 22.e6! Very impressive
22...Rxd5 [22...fxe6 23.Rxf5 gxf6 24.Bxf6+ Kf7 25.Bxd8+ exf5 26.Bxc7 also wins easily]
23.Nxd5+ Kd6 24.exf7 Kxd5 25.Re5+ Kd6 26.Rxf5 Ke6 27.Rg5 Kxf7
28.Be5 [28.c4 Rh7 29.f5 Be7 30.Rg6 Bf6 31.Bxf6 gxf6 32.h4 Rh8 is far from simple. Black also gets counterplay.]
28...c4 29.Bxc7 Bc5+ 30.Kf1 Rc8 31.Be5 g6 32.f5 gxf5 33.Rxh5 [Rightly avoiding 33.Rxf5+ Ke6 34.Rxh5 Rf8+ 35.Ke1 Rf2 ]
33...Rd8 34.Bc3 cxb3 Around here Nisipeanu was in severe time trouble, which explains the following mistakes.
35.cxb3 [Both players missed 35.Rxf5+ Kg6 36.Rf6+ Kg5 37.cxb3 with two extra pawns for White.]
35...Kg6 36.Rh8 Rd3 37.Rh3 Be3 [37...Rxh3 38.gxh3 is hopeless for Black]
38.Be1 [38.Be5 wins on the spot]
38...f4 39.Ke2 Rd8 40.g3 Rc8 41.gxf4 Bxf4 42.Rc3! Re8+ [42...Rxc3 43.Bxc3 Bxh2 44.Kd3 should be winning for White, see also next comment]
43.Kd1 Rd8+ 44.Kc2
44...Re8 [The bishops endgame after 44...Bxh2 45.Rc6+ Rd6 46.Rxd6+ Bxd6 47.Kd3 seems to be lost for Black. For instance: 47...Kf5 48.Kc4 a4 (48...Bc5 49.Bxa5 ) 49.b4 Bxb4 50.Bxb4 Ke6 51.Kb5 Kd7 52.Kxb6 Kc8 53.Bd6 Kd7 54.Bc7 and this endgame is mathematically winning for White, who will at some moment force Black to play a4-a3 and take the pawn with the bishop, while keeping the opponent's king away from square a8. 54...Ke6 55.Kc6 Ke7 56.Ba5 Ke6 57.Bb4 Ke5 58.Kd7 ]
45.Bg3 Be3 46.Kd3 Bc5 47.Kc4 a4 48.Kb5! axb3 49.axb3 Re2 50.Bc7 Re6 51.b4 Be7 52.Rc4 Kf5 53.Bxb6 Bd6 54.Bc7 1-0