Sergash: Nilssen was rated 2371 when he played this game, according to Chessbase. He got the International Master title.
<12.Be3 axb5=> White can secure a small advantage by castling quickly 12.Bd3! axb5 13.0-0 Paulo Sergio Lima (2115) vs Jose Claude De Souza (2285), Loures (Portugal) 1996, round 6, 0-1
<14.Qxd4?N Bg7! / > This is the first serious mistake in the game... and something new in the theory! 14.Bd3! Qa5+! 15.Kf1! Be7 16.Qe2!= / Alexander Motylev (2649) vs Andrey Shariyazdanov (2575), Qualifications for the 57th Championship of Russia 2004, round 5, 1-0
<15.Nxb5?!> 15.Be2 Qa5+ 16.Qd2 Bf6! 17.Qxa5 Rxa5 (Roberto Lo Presti (2073) vs Carlos Andres Obregon (2313), Qualifications for the Championship of Buenos Aires (Argentina) 2006, round 1, 0-1) 18.Rb1! Komodo 9.2 64 bits.
<16.Nc3? Bf6! > This is the final nail in the coffin! The only move was 16.Qd3! Komodo 9.2 64 bits. When Magnus played 16.Nc3?, he probably underestimated 18...Bxc3!