| Jun 10, 2026 | Vehi Bach | ½–½ | Petursson | Round 9: Vehi Bach, Victor Manuel - Petursson, Margeir | Caro-Kann Defense: Advance Variation | |
| Jun 8, 2026 | Petursson | 1–0 | Kolesar | Round 7: Petursson, Margeir - Kolesar, Milan | Réti Opening: Anglo-Slav Variation, with g3 | |
| Jun 7, 2026 | Astengo | 0–1 | Petursson | Round 6: Astengo, Corrado - Petursson, Margeir | Queen's Gambit Declined: Ragozin Defense, Alekhine Variation | |
| Jun 6, 2026 | Petursson | 0–1 | Pomes Marcet | Round 5: Petursson, Margeir - Pomes Marcet, Joan | Slav Defense: Modern Line | |
| Jun 5, 2026 | Gavrish | 0–1 | Petursson | Round 4: Gavrish, Leonid - Petursson, Margeir | Nimzo-Indian Defense: Normal Variation, Classical Defense | |
| Jun 4, 2026 | Petursson | ½–½ | Varley | Round 3: Petursson, Margeir - Varley, Peter | English Opening: King's English Variation | |
| Jun 3, 2026 | Jaderberg | 0–1 | Petursson | Round 2: Jaderberg, Bjorn - Petursson, Margeir | English Opening: Symmetrical Variation | |
| Jun 2, 2026 | Petursson | 1–0 | Germes | Round 1: Petursson, Margeir - Germes, Alain | English Opening | |
| Jun 1, 2026 | Petursson | ½–½ | Sturua | Round 8: Petursson, Margeir - Sturua, Zurab | English Opening: Agincourt Defense, Neo-Catalan Declined | |
| Apr 28, 2026 | Kosten | ½–½ | Petursson | Round 9: Kosten, Anthony C. - Petursson, Margeir | English Opening: Symmetrical Variation, Ultra-Symmetrical Variation | |
| Apr 27, 2026 | Petursson | 1–0 | Raetsky | Round 8: Petursson, Margeir - Raetsky, Alexander | Queen's Gambit Accepted: Janowski-Larsen Variation | |
| Apr 26, 2026 | Motuz | ½–½ | Petursson | Round 7: Motuz, Karol - Petursson, Margeir | Nimzo-Indian Defense: Normal Variation, Gligoric System, Bronstein Variation | |
| Apr 25, 2026 | Petursson | 1–0 | Haik | Round 6: Petursson, Margeir - Haik, Aldo | Kangaroo Defense | |
| Apr 23, 2026 | Moen | 0–1 | Petursson | Round 5: Moen, Ole Christian - Petursson, Margeir | Sicilian Defense: Hyperaccelerated Dragon | |
| Apr 21, 2026 | Ortega | 1–0 | Petursson | Round 3: Ortega, Lexy - Petursson, Margeir | Queen's Gambit Declined: Ragozin Defense, Alekhine Variation | |
| Apr 20, 2026 | Petursson | 1–0 | Townsend | Round 2: Petursson, Margeir - Townsend, M Paul | Catalan Opening: Open Defense, Classical Line | |
| Apr 19, 2026 | Petursson | 1–0 | Rogowski | Round 1: Petursson, Margeir - Rogowski, Jaroslaw | Slav Defense: Modern Line | |
| Mar 8, 2026 | Petursson | 0–1 | Thorfinnsson | Icelandic team chess championship premier league | Catalan Opening: Closed | |
| Mar 7, 2026 | Briem | 0–1 | Petursson | Icelandic team chess championship premier league | Nimzo-Indian Defense: Reshevsky Variation | |
| Mar 6, 2026 | Petursson | 1–0 | Arngrimsson | Icelandic team chess championship premier league | Caro-Kann Defense: Accelerated Panov Attack, Modern Variation | |
| Mar 5, 2026 | Petursson | 1–0 | Kjartansson | Icelandic team chess championship premier league | English Opening: Symmetrical Variation, Rubinstein Variation | |
| Oct 3, 2025 | Petursson | 0–1 | Welling | European individual senior chess championship 2025 - Open 65+, Rabac, Croatia | King's Indian Defense: Orthodox Variation | |
| Oct 2, 2025 | Fayard | 0–1 | Petursson | European individual senior chess championship 2025 - Open 65+, Rabac, Croatia | Nimzo-Indian Defense: Normal Variation, Botvinnik System | |
| Oct 1, 2025 | Petursson | ½–½ | Malmdin | European individual senior chess championship 2025 - Open 65+, Rabac, Croatia | Nimzo-Indian Defense: Rubinstein System | |
| Sep 30, 2025 | Suhogerlla | ½–½ | Petursson | European individual senior chess championship 2025 - Open 65+, Rabac, Croatia | Caro-Kann Defense: Advance Variation, Bronstein Variation | |
| Sep 29, 2025 | Petursson | ½–½ | Stoinev | European individual senior chess championship 2025 - Open 65+, Rabac, Croatia | Queen's Gambit Declined | |
| Sep 27, 2025 | Petursson | ½–½ | Brongers | European individual senior chess championship 2025 - Open 65+, Rabac, Croatia | King's Indian Defense: Makogonov Variation | |
| Feb 26, 2025 | Stohl | ½–½ | Petursson | WSTCC | Queen's Pawn Game: Symmetrical Variation | |
| Feb 25, 2025 | Petursson | ½–½ | Godena | WSTCC | Semi-Slav Defense | |
| Feb 24, 2025 | Petursson | ½–½ | Van Haastert | WSTCC | King's Indian Attack: Double Fianchetto | |
| Feb 23, 2025 | Conquest | 1–0 | Petursson | WSTCC | Sicilian Defense: Najdorf Variation | |
| Feb 21, 2025 | Csiszar | 0–1 | Petursson | WSTCC | Queen's Pawn Game: London System | |
| Feb 20, 2025 | Kotsur | 1–0 | Petursson | WSTCC | Bogo-Indian Defense: Vitolins Variation | |
| Feb 19, 2025 | Petursson | ½–½ | Ning | WSTCC | Bogo-Indian Defense: Retreat Variation | |
| Feb 17, 2025 | Petursson | 1–0 | Jackson | WSTCC | English Opening: Caro-Kann Defensive System | |
| Jan 4, 2025 | Kazarian | 0–1 | Petursson | 52nd Rilton Cup: Rilton Cup streamers games | Sicilian Defense: Hyperaccelerated Fianchetto | |
| Jan 3, 2025 | Petursson | 0–1 | Rakshitta Ravi | 52nd Rilton Cup | English Opening: Symmetrical Variation, Three Knights Variation | |
| Dec 30, 2024 | Logdahl | 1–0 | Petursson | 52nd Rilton Cup | Sicilian Defense: Closed | |
| Dec 29, 2024 | Petursson | ½–½ | Jain Kashish Manoj | 52nd Rilton Cup | King's Indian Attack: Yugoslav Variation | |
| Oct 25, 2024 | Petursson | ½–½ | Risting | 39th European Chess Club Cup | Indian Defense: Anti-Nimzo-Indian | |
| Oct 24, 2024 | Smeets | 1–0 | Petursson | 39th European Chess Club Cup | Sicilian Defense: Accelerated Dragon, Maróczy Bind, Gurgenidze Variation | |
| Oct 23, 2024 | Kokkila | 1–0 | Petursson | 39th European Chess Club Cup | Sicilian Defense: Najdorf Variation | |
| Oct 22, 2024 | Petursson | 1–0 | Gorodetzky | 39th European Chess Club Cup | Catalan Opening: Open Defense | |
| Oct 21, 2024 | Petursson | ½–½ | Skytte | 39th European Chess Club Cup | Tarrasch Defense | |
| Jul 11, 2024 | Petursson | ½–½ | Ginsburg | 50-1 | English Opening | |
| Jul 10, 2024 | Petursson | 1–0 | Motuz | 50-1 | Catalan Opening: Open Defense | |
| Jul 9, 2024 | Shabalov | 1–0 | Petursson | 50-1 | Sicilian Defense: Najdorf Variation | |
| Jul 7, 2024 | Barron | 0–1 | Petursson | 50-1 | Sicilian Defense: Prins Variation | |
| Jul 6, 2024 | Petursson | 1–0 | Bellia | 50-1 | Queen's Gambit Declined: Ragozin Defense | |
| Jul 5, 2024 | Petursson | ½–½ | Emms | 50-1 | Queen's Gambit Declined: Exchange Variation, Reshevsky Variation | |
| Jul 4, 2024 | Petursson | 1–0 | Fleish | 50-1 | King's Indian Defense: Normal Variation, Rare Defenses | |
| Jul 2, 2024 | Forgo | 0–1 | Petursson | 50-1 | Sicilian Defense: Najdorf Variation, Amsterdam Variation | |
| May 15, 2024 | Petursson | 1–0 | Jaksland | European Senior Team Chess Championship 2024 - Section 50 + | English Opening: Symmetrical Variation, Rubinstein Variation | |
| May 13, 2024 | Petursson | 0–1 | Flear | European Senior Team Chess Championship 2024 - Section 50 + | Réti Opening | |
| May 12, 2024 | Motuz | 0–1 | Petursson | European Senior Team Chess Championship 2024 - Section 50 + | Bogo-Indian Defense: Grünfeld Variation | |
| May 11, 2024 | Petursson | ½–½ | Godena | European Senior Team Chess Championship 2024 - Section 50 + | Réti Opening: Réti Accepted | |
| May 10, 2024 | Varga | 1–0 | Petursson | European Senior Team Chess Championship 2024 - Section 50 + | Sicilian Defense: Prins Variation | |
| May 9, 2024 | Nikcevic | 1–0 | Petursson | European Senior Team Chess Championship 2024 - Section 50 + | Queen's Indian Defense: Kasparov Variation | |
| May 8, 2024 | Beaumont | 0–1 | Petursson | European Senior Team Chess Championship 2024 - Section 50 + | Catalan Opening | |
| Mar 15, 2024 | Petursson | 1–0 | Sobol | Charity Event for Memory Ukrainian Ches | Queen's Gambit Declined: Ragozin Defense | |
| Mar 15, 2024 | Petursson | 0–1 | Sakun | Charity Event for Memory Ukrainian Ches | Queen's Gambit Declined | |
| Mar 15, 2024 | Petursson | ½–½ | Andriienko | Charity Event for Memory Ukrainian Ches | Nimzo-Indian Defense: Kmoch Variation | |
| Mar 15, 2024 | Karpinets | ½–½ | Petursson | Charity Event for Memory Ukrainian Ches | Sicilian Defense: Old Sicilian | |
| Mar 15, 2024 | Fainkihen | 0–1 | Petursson | Charity Event for Memory Ukrainian Ches | Sicilian Defense: Hyperaccelerated Dragon | |
| Mar 15, 2024 | Bagiryan | 0–1 | Petursson | Charity Event for Memory Ukrainian Ches | Sicilian Defense: Closed | |
| Oct 20, 2024 | Gukesh D | 1–0 | Petursson | Round 1: Gukesh D - Petursson, Margeir | Bogo-Indian Defense: Grünfeld Variation | |
| Oct 4, 2023 | Stankovic | ½–½ | Petursson | European Chess Club Cup 2023 | Sicilian Defense: Najdorf Variation, Amsterdam Variation | |
| Oct 2, 2023 | Lagarde | 1–0 | Petursson | European Chess Club Cup 2023 | Sicilian Defense: Hyperaccelerated Fianchetto | |
| Mar 19, 2023 | Petursson | 1–0 | Hansen | Icelandic Team Championship | Nimzo-Indian Defense: Kmoch Variation | |
| Mar 18, 2023 | Tan | ½–½ | Petursson | Icelandic Team Championship | Sicilian Defense: Alapin Variation, Barmen Defense | |
| Mar 17, 2023 | Petursson | 1–0 | Thorfinnsson | Icelandic Team Championship | Nimzo-Indian Defense: Kmoch Variation | |
| Jan 5, 2023 | Lindberg | 0–1 | Petursson | 50th Rilton Cup | Sicilian Defense: Accelerated Dragon, Maróczy Bind, Gurgenidze Variation | |
| Jan 4, 2023 | Petursson | ½–½ | Livaic | 50th Rilton Cup | King's Indian Defense: Averbakh Variation, Modern Defense | |
| Jan 3, 2023 | Sasikiran | ½–½ | Petursson | 50th Rilton Cup | Bogo-Indian Defense: Grünfeld Variation | |
| Jan 2, 2023 | Petursson | ½–½ | Galperin | 50th Rilton Cup | Nimzo-Indian Defense: Kmoch Variation | |
| Dec 31, 2022 | Westerberg | ½–½ | Petursson | 50th Rilton Cup | Sicilian Defense: Chekhover Variation | |
| Dec 30, 2022 | Petursson | ½–½ | Seo | 50th Rilton Cup | Nimzo-Indian Defense: Kmoch Variation | |
| Dec 29, 2022 | Ruiz Buendia | 0–1 | Petursson | 50th Rilton Cup | Sicilian Defense: Najdorf Variation, English Attack | |
| Dec 28, 2022 | Petursson | ½–½ | Shohat | 50th Rilton Cup | King's Indian Defense: Averbakh Variation, Modern Defense | |
| Dec 18, 2022 | Petursson | ½–½ | Beliavsky | European Rapid Chess Championship 2022 | Catalan Opening: Open Defense, Classical Line | |
| Dec 18, 2022 | Petursson | ½–½ | Minald | Katowice | English Opening: King's English Variation | |
| Dec 18, 2022 | Svane | ½–½ | Petursson | European Rapid Chess Championship 2022 | Sicilian Defense: Accelerated Dragon, Maróczy Bind, Gurgenidze Variation | |
| Dec 18, 2022 | Hovhannisyan | 1–0 | Petursson | European Rapid Chess Championship 2022 | Sicilian Defense: Hyperaccelerated Dragon | |
| Dec 18, 2022 | Bochnickova | 0–1 | Petursson | Katowice | Sicilian Defense: Accelerated Dragon, Maróczy Bind | |
| Dec 17, 2022 | Petursson | 0–1 | Niezhentsev | European Rapid Championship | English Opening: King's English Variation, Four Knights Variation, Fianchetto Line | |
| Dec 17, 2022 | Petursson | 1–0 | Samborski | Katowice | French Defense: Winawer Variation | |
| Dec 17, 2022 | Petursson | 1–0 | Hnatyshyn | Katowice | Queen's Gambit Declined: Three Knights Variation | |
| Dec 17, 2022 | Modlich | 0–1 | Petursson | Katowice | Sicilian Defense: Accelerated Dragon, Maróczy Bind | |
| Dec 17, 2022 | Krivenko | 0–1 | Petursson | Katowice | Sicilian Defense: Hyperaccelerated Fianchetto | |
| Oct 16, 2022 | Gunnarsson | ½–½ | Petursson | Icelandic Team Championship | English Opening: Symmetrical Variation, Ultra-Symmetrical Variation | |
| Oct 15, 2022 | Stefansson | ½–½ | Petursson | Icelandic Team Championship | Sicilian Defense: Accelerated Dragon, Maróczy Bind, Gurgenidze Variation | |
| Oct 14, 2022 | Petursson | ½–½ | Thorfinnsson | Icelandic Team Championship | English Opening: King's English Variation | |
| Oct 4, 2022 | Petursson | ½–½ | Nihal | ECCC_22 | English Opening: King's English Variation | |
| Sep 24, 2021 | Mikhalchishin | ½–½ | Petursson | 36th European Club Cup | Sicilian Defense: Hyperaccelerated Dragon | |
| Sep 23, 2021 | Petursson | 0–1 | Roiz | 36th European Club Cup | English Opening: Symmetrical Variation, Rubinstein Variation | |
| Sep 22, 2021 | Petursson | 1–0 | Dragicevic | 36th European Club Cup | ? | |
| Sep 21, 2021 | Risteski | 0–1 | Petursson | 36th European Club Cup | Sicilian Defense: Hyperaccelerated Dragon | |
| Sep 20, 2021 | Petursson | * | Pacher | 36th European Club Cup | ? | |
| Sep 19, 2021 | Petursson | * | Dinev | 36th European Club Cup | ? | |
| Sep 18, 2021 | Ragger | 1–0 | Petursson | 36th European Club Cup | Sicilian Defense: Hyperaccelerated Dragon | |