De Firmian, Nick E. (USA) - Sousa, Helsio Paulo 1-0, Oslo Chess International, GM-group (1), Oslo, 2011.10.02
De Firmian, Nick E. (USA) - Østmoe, Geir Sune Tallaksen 1/2-1/2, Oslo Chess International, GM-group (3), Oslo, 2011.10.02
De Firmian, Nick E. (USA) - Volkov, Sergey (RUS) 1/2-1/2, Oslo Chess International, GM-group (5), Oslo, 2011.10.02
De Firmian, Nick E. (USA) - Welling, Gerard (NED) 0-1, Oslo Chess International, GM-group (7), Oslo, 2011.10.02
De Firmian, Nick E. (USA) - Gullaksen, Eirik T. 1-0, Oslo Chess International, GM-group (8), Oslo, 2011.10.02
De Firmian, Nick E. (USA) - Umudova, Nargiz (AZE) 1/2-1/2, Jubileumsturnering, GM (9), Gjøvik, 2009.01.07
De Firmian, Nick E. (USA) - Mchedlishvili, Mikheil (GEO) 1/2-1/2, Jubileumsturnering, GM (7), Gjøvik, 2009.01.05
De Firmian, Nick E. (USA) - Kulaots, Kaido (EST) 1/2-1/2, Jubileumsturnering, GM (5), Gjøvik, 2009.01.02
De Firmian, Nick E. (USA) - Devereaux, Maxim (ENG) 1-0, Jubileumsturnering, GM (4), Gjøvik, 2009.01.01
De Firmian, Nick E. (USA) - Prakken, Gerrit (NED) 1-0, Jubileumsturnering, GM (2), Gjøvik, 2008.12.30
De Firmian, Nick E. (USA) - Haugstad, Espen 1-0, Arctic Chess Challenge (9), Tromsø, 2007.08.12
De Firmian, Nick E. (USA) - Karlsen, Sverre 1-0, Arctic Chess Challenge (8), Tromsø, 2007.08.11
De Firmian, Nick E. (USA) - Getz, Nicolai 1-0, Arctic Chess Challenge (5), Tromsø, 2007.08.08
De Firmian, Nick E. (USA) - Pedersen, Johnny Karl 1-0, Arctic Chess Challenge (3), Tromsø, 2007.08.06
De Firmian, Nick E. (USA) - Thingstad, Even 0-1, Arctic Chess Challenge (1), Tromsø, 2007.08.04
De Firmian, Nick E. (USA) - Forså, Espen 1-0, Politiken Cup (5), København (DEN), 2005.07.19
De Firmian, Nick E. (USA) - Carlsen, Magnus Øen 1/2-1/2, Politiken Cup (6), København (DEN), 2004.07.28
De Firmian, Nick E. (USA) - Harstad, Christian 1-0, Politiken Cup (2), København (DEN), 2004.07.25
De Firmian, Nick E. (USA) - Carlsen, Magnus Øen 0-1, It (cat.14) (8), Malmö (SWE)/Københamn (DEN), 2004.05.08
De Firmian, Nick E. (USA) - Gullaksen, Eirik T. 1-0, Politiken Cup (7), København (DEN), 2003.07.20
De Firmian, Nick E. (USA) - Lugovoi, Alexei (RUS) 0-1, Gausdal Classics, GM group (11), Gausdal, 2003.04.11
De Firmian, Nick E. (USA) - Pähtz, Elisabeth (GER) 1/2-1/2, Gausdal Classics, GM group (9), Gausdal, 2003.04.09
De Firmian, Nick E. (USA) - Lie, Kjetil A. 1-0, Gausdal Classics, GM group (7), Gausdal, 2003.04.08
De Firmian, Nick E. (USA) - Bluvshtein, Mark (CAN) 1-0, Gausdal Classics, GM group (5), Gausdal, 2003.04.06
De Firmian, Nick E. (USA) - Berg, Emanuel (SWE) 1/2-1/2, Gausdal Classics, GM group (2), Gausdal, 2003.04.04
De Firmian, Nick E. (USA) - Hreinsson, Hlidar Thor (ISL) 1-0, Troll Masters, I (2), Gausdal, 1999
De Firmian, Nick E. (USA) - Hersvik, Daniel 1-0, Troll Masters, I (4), Gausdal, 1999
De Firmian, Nick E. (USA) - Ornstein, Axel (SWE) 1/2-1/2, Troll Masters, I (6), Gausdal, 1999
De Firmian, Nick E. (USA) - Borge, Nikolaj (DEN) 1-0, Troll Masters, I (8), Gausdal, 1999
De Firmian, Nick E. (USA) - Riska-Pedersen, Jone 1-0, Troll Masters, I (2), Gausdal, 1995
De Firmian, Nick E. (USA) - Olesen, Martin (DEN) 1-0, Troll Masters, I (4), Gausdal, 1995
De Firmian, Nick E. (USA) - Gausel, Einar 1-0, Troll Masters, I (6), Gausdal, 1995
De Firmian, Nick E. (USA) - Rogers, Ian (AUS) 1/2-1/2, Troll Masters, I (7), Gausdal, 1995
De Firmian, Nick E. (USA) - Makarichev, Sergey (RUS) 0-1, Internasjonal turnering, Oslo, 1986
De Firmian, Nick E. (USA) - Arnason, Jon L. (ISL) 0-1, Internasjonal turnering (16), Oslo, 1984
De Firmian, Nick E. (USA) - Miles, Anthony J. (ENG) 1/2-1/2, Internasjonal turnering, Oslo, 1984
De Firmian, Nick E. (USA) - Huebner, Robert Dr (GER) 1/2-1/2, Internasjonal turnering, Oslo, 1984
De Firmian, Nick E. (USA) - Øgaard, Leif 1-0, Gausdal, 1983
De Firmian, Nick E. (USA) - Westerinen, Heikki (FIN) 1-0, Internasjonal turnering (1), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Wedberg, Tom (SWE) 1/2-1/2, Internasjonal turnering (3), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Åkesson, Ralf (SWE) 1-0, Internasjonal turnering (5), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Thorsteins, Karl (ISL) 1-0, Internasjonal turnering (7), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Adler, Bo (SWE) 1-0, Young Masters (1), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Tisdall, Jonathan D. 1/2-1/2, Young Masters (3), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Cramling, Dan (SWE) 1-0, Young Masters (5), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Kudrin, Sergey (USA) 0-1, Young Masters (7), Gausdal, 1982.08
De Firmian, Nick E. (USA) - Plaskett, James (ENG) 1/2-1/2, Arnold Cup (1), Gausdal, 1982.04
De Firmian, Nick E. (USA) - Stigar, Petter 1-0, Arnold Cup (3), Gausdal, 1982.04
De Firmian, Nick E. (USA) - Iskov, Gert (DEN) 1-0, Arnold Cup (4), Gausdal, 1982.04
De Firmian, Nick E. (USA) - Stean, Michael F (ENG) 1/2-1/2, Arnold Cup (7), Gausdal, 1982.04
De Firmian, Nick E. (USA) - Øgaard, Leif 1-0, Arnold Cup (8), Gausdal, 1982.04
De Firmian, Nick E. (USA) - Cramling, Dan (SWE) 1/2-1/2, Internasjonal turnering, Gausdal, 1980.08
Antall partier: 52