| Apr 5, 2026 | Petersen | 0–1 | Peyrer | Grenke Chess Festival 2026 Open | Sicilian Defense: Moscow Variation | |
| Apr 4, 2026 | Postlmayer | 1–0 | Petersen | Grenke Chess Festival 2026 Open | Queen's Gambit Declined: Harrwitz Attack | |
| Apr 4, 2026 | Petersen | ½–½ | Ginsburg | Grenke Chess Festival 2026 Open | French Defense: Tarrasch Variation, Open System, Euwe-Keres Line | |
| Nov 16, 2025 | Mazurtsova | 0–1 | Petersen | Round 11: Mazurtsova, Margarita - Petersen, Marcel | English Opening: Anglo-Indian Defense, Hedgehog System | |
| Nov 16, 2025 | Petersen | 0–1 | Koellner | Round 10: Petersen, Marcel - Koellner, Ruben Gideon | Philidor Defense: Lion Variation | |
| Nov 16, 2025 | Petersen | 1–0 | Brockhoff | Round 9: Petersen, Marcel - Brockhoff, Moritz | Bishop's Opening: Vienna Hybrid | |
| Nov 16, 2025 | Jiron | 0–1 | Petersen | Round 8: Jiron, Valerio - Petersen, Marcel | English Opening: Anglo-Indian Defense, King's Knight Variation | |
| Nov 15, 2025 | Petrov | 1–0 | Petersen | 3. Berlin U25-Open Rapid | English Opening: Anglo-Indian Defense | |
| Nov 15, 2025 | Petersen | 0–1 | Bayar | Round 7: Petersen, Marcel - Bayar, Mehmet | Bishop's Opening: Boi Variation | |
| Nov 15, 2025 | Eilenberg | 1–0 | Petersen | Round 6: Eilenberg, Jonas - Petersen, Marcel | Nimzo-Indian Defense: Classical Variation, Noa Variation | |
| Nov 15, 2025 | Petersen | 1–0 | Mimkes | Round 5: Petersen, Marcel - Mimkes, Antal | Sicilian Defense: French Variation | |
| Nov 15, 2025 | Makarov | 0–1 | Petersen | Round 4: Makarov, Glib - Petersen, Marcel | Queen's Pawn Game: London System | |
| Nov 15, 2025 | Petersen | 1–0 | Schaefer | 3. Berlin U25-Open Rapid | Sicilian Defense: Closed, Traditional | |
| Nov 15, 2025 | Petersen | 1–0 | Tamke | 3. Berlin U25-Open Rapid | Caro-Kann Defense: Panov Attack | |
| Nov 15, 2025 | Petersen | 1–0 | Tamke | 3. Berlin U25-Open Rapid | Caro-Kann Defense: Panov Attack | |
| Nov 15, 2025 | Petersen | ½–½ | Schaefer | 3. Berlin U25-Open Rapid | Bishop's Opening: Vienna Hybrid | |
| Nov 15, 2025 | Petrov | 1–0 | Petersen | 3. Berlin U25-Open Rapid | English Opening: Anglo-Indian Defense, King's Knight Variation | |
| Nov 15, 2025 | Poltorak | 1–0 | Peyrer | 3. Berlin U25-Open Rapid | Sicilian Defense: Closed, Traditional | |
| Nov 15, 2025 | Melde | 1–0 | Gholami Orimi | 3. Berlin U25-Open Rapid | English Opening: Anglo-Indian Defense | |
| Nov 14, 2025 | Mazurtsova | 1–0 | Petersen | Round 13 & Semifinals Armageddon: Mazurtsova, Margarita - Petersen, Marcel | English Opening: Anglo-Indian Defense, Hedgehog System | |
| Nov 14, 2025 | Petersen | 0–1 | Hrebenshchykova | Round 12 & Semifinals: Petersen, Marcel - Hrebenshchykova, Yelyzaveta | Sicilian Defense: French Variation | |
| Nov 14, 2025 | Sieber | 0–1 | Petersen | Round 11 & Quarterfinals Armageddon: Sieber, Fiona - Petersen, Marcel | Scotch Game: Mieses Variation | |
| Nov 14, 2025 | Petersen | 1–0 | Albersmann | Round 10 & Quarterfinals: Petersen, Marcel - Albersmann, Rene | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Nov 14, 2025 | Hovhannisyan | 1–0 | Petersen | Round 9: Hovhannisyan, Artur - Petersen, Marcel | Ruy Lopez: Morphy Defense, Fianchetto Defense Deferred | |
| Nov 14, 2025 | Petersen | 0–1 | Vardanyan | Round 8: Petersen, Marcel - Vardanyan, Aras | Sicilian Defense: Moscow Variation, Main Line | |
| Nov 14, 2025 | Walz | 0–1 | Petersen | Round 7: Walz, Fabian - Petersen, Marcel | Catalan Opening: Closed | |
| Nov 14, 2025 | Petersen | 1–0 | Dubsky | Round 6: Petersen, Marcel - Dubsky, Lukas | Sicilian Defense: French Variation | |
| Nov 14, 2025 | Henning | 1–0 | Petersen | Round 5: Henning, Marvin - Petersen, Marcel | Ruy Lopez: Morphy Defense, Fianchetto Defense Deferred | |
| Nov 14, 2025 | Petersen | 1–0 | Makarov | Round 4: Petersen, Marcel - Makarov, Glib | Scandinavian Defense | |
| Jul 31, 2025 | Prazak | 1–0 | Petersen | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | Italian Game: Classical Variation, Giuoco Pianissimo, with a6 | |
| Jul 30, 2025 | Petersen | ½–½ | Hrbek | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack, Fianchetto Variation | |
| Jul 29, 2025 | Piesik | ½–½ | Petersen | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | King's Indian Attack | |
| Jul 28, 2025 | Petersen | 1–0 | Gnojek | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | Sicilian Defense: Moscow Variation, Main Line | |
| Jul 27, 2025 | Cvek | ½–½ | Petersen | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Jul 26, 2025 | Petersen | ½–½ | Kulon | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | Sicilian Defense: French Variation | |
| Apr 15, 2025 | Petersen | ½–½ | Williams | Reykjavik Open 2025 | Sicilian Defense: French Variation | |
| Apr 14, 2025 | Kunin | ½–½ | Petersen | Reykjavik Open 2025 | Hungarian Opening | |
| Apr 13, 2025 | Petersen | ½–½ | Thorhallsson | Reykjavik Open 2025 | Sicilian Defense: French Variation | |
| Apr 13, 2025 | Benavente | 0–1 | Petersen | Reykjavik Open 2025 | Queen's Pawn Game: Symmetrical Variation | |
| Apr 12, 2025 | Petersen | 1–0 | Levin | Reykjavik Open 2025 | Petrov's Defense: Three Knights Game | |
| Apr 11, 2025 | Larkin | 1–0 | Petersen | Reykjavik Open 2025 | Italian Game: Classical Variation, Giuoco Pianissimo | |
| Apr 10, 2025 | Petersen | 0–1 | Kilic | Reykjavik Open 2025 | Sicilian Defense: Moscow Variation, Moscow Gambit | |
| Apr 10, 2025 | Niermann | 0–1 | Petersen | Reykjavik Open 2025 | English Opening: Agincourt Defense | |
| Apr 9, 2025 | Petersen | 1–0 | Zhang | Reykjavik Open 2025 | French Defense: Tarrasch Variation, Open System, Euwe-Keres Line | |
| Apr 6, 2024 | Thiede | 1–0 | Petersen | Round 8: Thiede, Lars - Petersen, Marcel | Zukertort Opening: Kingside Fianchetto | |
| Apr 1, 2024 | Klenburg | 1–0 | Petersen | Round 4: Klenburg, Michael - Petersen, Marcel | King's Indian Attack: Pachman System | |
| Mar 31, 2024 | Baldauf | 1–0 | Petersen | Round 2: Baldauf, Marco - Petersen, Marcel | English Opening: Anglo-Indian Defense, King's Knight Variation | |
| Mar 30, 2024 | Petersen | ½–½ | Poltorak | Round 1: Petersen, Marcel - Poltorak, Sebastian | Sicilian Defense: French Variation | |
| Oct 27, 2024 | Petersen | 1–0 | Bui | Round 9: Petersen, Marcel - Bui, Bao Anh Le | Sicilian Defense: French Variation | |
| Oct 26, 2024 | Fizer | 0–1 | Petersen | Round 8: Fizer, Marek - Petersen, Marcel | Ruy Lopez: Morphy Defense, Fianchetto Defense Deferred | |
| Oct 25, 2024 | Petersen | ½–½ | Knuedel | Round 7: Petersen, Marcel - Knuedel, Torben | Sicilian Defense: Hyperaccelerated Fianchetto | |
| Oct 24, 2024 | Petersen | 0–1 | Degenhard | Round 5: Petersen, Marcel - Degenhard, Simon | Italian Game: Classical Variation, Greco Gambit | |
| Oct 24, 2024 | Hoffmann | 0–1 | Petersen | Round 6: Hoffmann, Kay - Petersen, Marcel | Indian Defense: Anti-Nimzo-Indian | |
| Oct 23, 2024 | Prazak | 1–0 | Petersen | Round 4: Prazak, Daniel - Petersen, Marcel | Italian Game: Classical Variation, Greco Gambit, Anderssen Variation | |
| Oct 22, 2024 | Petersen | ½–½ | Polster | Round 3: Petersen, Marcel - Polster, Christian | Pirc Defense | |
| Oct 22, 2024 | Wu | ½–½ | Petersen | Round 2: Wu, Yixing - Petersen, Marcel | King's Indian Attack: Yugoslav Variation | |
| Oct 21, 2024 | Petersen | ½–½ | Stelmaszyk | Round 1: Petersen, Marcel - Stelmaszyk, Nico | Sicilian Defense: French Variation | |
| Jun 1, 2023 | Peyrer | 1–0 | Petersen | 1st Munich Pfingst Open | King's Indian Attack: Symmetrical Defense | |
| May 31, 2023 | Petersen | ½–½ | Fedorovsky | 1st Munich Pfingst Open | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack, Fianchetto Variation | |
| Jul 31, 2021 | Koziorowicz | 1–0 | Petersen | Czech Open 2021 - A Pardubice Open | Zukertort Opening | |
| Jul 24, 2021 | Kusa | 1–0 | Petersen | Czech Open 2021 - A Pardubice Open | Sicilian Defense: Moscow Variation | |
| — | Petersen | 0–1 | Korshunov | CZECH OPEN 2025 - A - PARDUBICE OPEN - open grandmaster tournament | Four Knights Game: Glek System | |
