John C Yoos vs Johann Hjartarson
Reykjavik Open Reykjavik ISL round 3 1996.03.04
King’s Gambit Accepted: Greco Gambit 0-1

Johann Hjartarson vs Gyula Sax
Reykjavik World Cup Reykjavik ISL round 13 1988.10.18
Queen’s Indian Defense: Buerger Variation 1/2-1/2

Johann Hjartarson vs Samu Ristoja
Reykjavik Open Reykjavik ISL round 2.22 2017.04.20
Queen’s Gambit Declined: Ragozin Defense, Vienna Variation 1-0

Michael Adams vs Johann Hjartarson
Paris PCA/Intel-GP Paris FRA round 1.2 1994.11.11
Sicilian Defense: Kan Variation, Gipslis Variation 0-1

Zoltan Almasi vs Johann Hjartarson
World Rapid Championship Berlin GER round 1.30 2015.10.10
Ruy Lopez: Brix Variation 1-0

Johann Hjartarson vs Predrag Nikolic
Reykjavik World Cup Reykjavik ISL round 15 1988.10.21
Pirc Defense: Classical Variation 1-0

Johann Hjartarson vs Valery Kazakouski
23rd European Teams Terme Catez SLO round 3.17 2021.11.14
Queen’s Gambit Declined: Ragozin Defense 1/2-1/2

Smbat Gariginovich Lputian vs Johann Hjartarson
Biel Interzonal Biel SUI round 13 1993.07.31
Nimzo-Indian Defense: Three Knights Variation, Duchamp Variation 1-0

Simen Agdestein vs Johann Hjartarson
Interpolis 13th Tilburg NED round 5 1989.09.20
Nimzo-Indian Defense 1/2-1/2

Ulf Andersson vs Johann Hjartarson
Belfort World Cup Belfort FRA round 4 1988.06.18
English Opening: Anglo-Indian Defense 0-1