| Jun 26, 2026 | Papaioannou | 0–1 | Biyiksiz | Round 11: Papaioannou, Dimitrios - Biyiksiz, Ali Batuhan | Ruy Lopez: Morphy Defense, Cozio Defense | |
| Jun 25, 2026 | Daulet | ½–½ | Papaioannou | Round 10: Daulet, Alikhan - Papaioannou, Dimitrios | King's Indian Defense: Orthodox Variation | |
| Jun 24, 2026 | Iunusov | 0–1 | Papaioannou | Round 9: Iunusov, Nuriddin - Papaioannou, Dimitrios | Sicilian Defense: Richter-Rauzer Variation, Modern Variation | |
| Jun 23, 2026 | Papaioannou | ½–½ | Lopez Garcia | World Youth Chess Championship 2026 U18 Open | Ruy Lopez: Morphy Defense, Norwegian Variation | |
| Jun 22, 2026 | Bayantas | 1–0 | Papaioannou | Round 7: Bayantas, Asman - Papaioannou, Dimitrios | Queen's Gambit Declined | |
| Jun 20, 2026 | Papaioannou | ½–½ | Religa | Round 6: Papaioannou, Dimitrios - Religa, Marek | French Defense: Steinitz Variation, Boleslavsky Variation | |
| Jun 19, 2026 | Imomkuzieva | ½–½ | Papaioannou | Round 5: Imomkuzieva, Nilufarkhon - Papaioannou, Dimitrios | Ruy Lopez: Morphy Defense, Steinitz Deferred | |
| Jun 18, 2026 | Papaioannou | ½–½ | Dumanuly | Round 4: Papaioannou, Dimitrios - Dumanuly, Sultanbeibarys | Ruy Lopez: Closed, Anti-Marshall | |
| Jun 17, 2026 | Papaioannou | 1–0 | Brunetti | Round 3: Papaioannou, Dimitrios - Brunetti, Alessandro | Ruy Lopez: Morphy Defense, Anderssen Variation | |
| Jun 16, 2026 | Coetsee | 0–1 | Papaioannou | Round 2: Coetsee, Dewald - Papaioannou, Dimitrios | Sicilian Defense: Kalashnikov Variation | |
| Jun 15, 2026 | Papaioannou | 0–1 | Topuz | Round 1: Papaioannou, Dimitrios - Topuz, Mirac Melih | Sicilian Defense: Delayed Alapin Variation, with e6 | |
| Apr 26, 2026 | Papadopoulos | 1–0 | Papaioannou | Finals: Papadopoulos, Panayotis - Papaioannou, Dimitrios | Nimzo-Larsen Attack: Indian Variation | |
| Apr 25, 2026 | Tsorbatzoglou | 0–1 | Papaioannou | Semifinals: Tsorbatzoglou, Theodoros - Papaioannou, Dimitrios | Torre Attack: Fianchetto Defense | |
| Feb 11, 2026 | Katsanis | 1–0 | Papaioannou | Round 4: Katsanis, Vasileios Dim - Papaioannou, Dimitrios | King's Indian Defense: Semi-Averbakh System | |
| Feb 11, 2026 | Kassios | 1–0 | Papaioannou | Round 3: Kassios, Dimitrios - Papaioannou, Dimitrios | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Nov 7, 2025 | kiladze | 0–1 | Papaioannou | Round 9: kiladze, Luka - Papaioannou, Dimitrios | Bishop's Opening: Vienna Hybrid | |
| Nov 6, 2025 | Papasimakopoulos | 1–0 | Papaioannou | Round 3: Papasimakopoulos, Alexandros - Papaioannou, Dimitrios | Zukertort Opening: Sicilian Invitation | |
| Nov 6, 2025 | Papaioannou | 0–1 | Papasimakopoulos | Round 3: Papaioannou, Dimitrios - Papasimakopoulos, Alexandros | French Defense: Winawer Variation, Advance Variation | |
| Nov 2, 2025 | Rustamov | 1–0 | Papaioannou | Round 5: Rustamov, Rustam - Papaioannou, Dimitrios | Sicilian Defense: Kalashnikov Variation | |
| Oct 31, 2025 | Perossa | 1–0 | Papaioannou | Round 3: Perossa, Nicolas - Papaioannou, Dimitrios | Sicilian Defense: Najdorf Variation, English Attack, Anti-English | |
| Oct 14, 2025 | Pashikyan | 1–0 | Papaioannou | Round 10: Pashikyan, Rudolf - Papaioannou, Dimitrios | King's Indian Defense: Makogonov Variation | |
| Oct 12, 2025 | Akhilbay | 1–0 | Papaioannou | Round 8: Akhilbay, Imangali - Papaioannou, Dimitrios | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Oct 4, 2025 | Ansat | ½–½ | Papaioannou | Round 1: Ansat, Aldiyar - Papaioannou, Dimitrios | Ruy Lopez: Morphy Defense, Neo-Arkhangelsk Variation | |
| Sep 5, 2025 | Alexiadis | ½–½ | Papaioannou | Nono turno: Alexiadis, Hristos - Papaioannou, Dimitrios | Sicilian Defense: Accelerated Dragon, Maróczy Bind | |
| Sep 4, 2025 | Papaioannou | ½–½ | Schernthaner | Ottavo turno: Papaioannou, Dimitrios - Schernthaner, David | Sicilian Defense: Najdorf Variation, English Attack | |
| Sep 3, 2025 | Papaioannou | 0–1 | Raja Harshit | Settimo turno: Papaioannou, Dimitrios - Raja Harshit | Bogo-Indian Defense: Retreat Variation | |
| Sep 2, 2025 | Alonso | 0–1 | Papaioannou | Sesto turno: Alonso, Salvador - Papaioannou, Dimitrios | Italian Game: Classical Variation, Giuoco Pianissimo | |
| Sep 2, 2025 | Papaioannou | ½–½ | Gschnitzer | Quinto turno: Papaioannou, Dimitrios - Gschnitzer, Adrian | Sicilian Defense: Najdorf Variation, Adams Attack | |
| Sep 1, 2025 | Dulio Collutiis | 0–1 | Papaioannou | Quarto turno: Dulio Collutiis - Papaioannou, Dimitrios | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack, Fianchetto Variation | |
| Jul 28, 2025 | Papaioannou | 0–1 | Bosiocic | Round 1: Papaioannou, Dimitrios - Bosiocic, Marin | Sicilian Defense: Lasker-Pelikan Variation, Sveshnikov Variation | |
| Jul 17, 2025 | Papaioannou | 0–1 | Avinash Ramesh | Round 4: Papaioannou, Dimitrios - Avinash Ramesh | French Defense: Classical Variation, Burn Variation | |
| Jul 4, 2025 | Papaioannou | ½–½ | Rahmanidis | Round 7: Papaioannou, Dimitrios - Rahmanidis, Petros | Four Knights Game: Glek System | |
| Jul 3, 2025 | Georgakopoulos | 1–0 | Papaioannou | Round 3: Georgakopoulos, Nikolaos K. - Papaioannou, Dimitrios | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack, Fianchetto Variation | |
| Jul 3, 2025 | Koutlas | ½–½ | Papaioannou | Round 2: Koutlas, Nikolaos - Papaioannou, Dimitrios | Queen's Gambit Declined | |
| Jul 3, 2025 | Tzagarakis | 1–0 | Papaioannou | Round 5: Tzagarakis, Panagiotis - Papaioannou, Dimitrios | Ruy Lopez: Morphy Defense, Modern Steinitz Defense | |
| Jan 8, 2025 | Papaioannou | 1–0 | Mantazis | Round 9: Papaioannou, Dimitrios - Mantazis, Georgios Rafail | Ruy Lopez: Steinitz Defense | |
| Jan 7, 2025 | Karamichos | ½–½ | Papaioannou | Round 8: Karamichos, Michail - Papaioannou, Dimitrios | King's Indian Defense: Normal Variation, King's Knight Variation | |
| Jan 6, 2025 | Alepoudeas | ½–½ | Papaioannou | Round 7: Alepoudeas, Stylianos - Papaioannou, Dimitrios | King's Indian Defense: Normal Variation, Standard Development | |
| Jan 5, 2025 | Papaioannou | ½–½ | Tagkaloglou | Round 5: Papaioannou, Dimitrios - Tagkaloglou, Savvas Stefanos | Italian Game: Classical Variation, Giuoco Pianissimo | |
| Jan 5, 2025 | Papaioannou | 1–0 | Antonioudakis | Round 6: Papaioannou, Dimitrios - Antonioudakis, Georgios | English Opening: Agincourt Defense, Neo-Catalan Declined | |
| Jan 4, 2025 | Moysidis | 0–1 | Papaioannou | Round 4: Moysidis, Anastasios - Papaioannou, Dimitrios | King's Indian Defense: Normal Variation | |
| Jan 3, 2025 | Papaioannou | ½–½ | Margaritis | Round 3: Papaioannou, Dimitrios - Margaritis, Ioannis M | Bogo-Indian Defense: Nimzowitsch Variation | |
| Jan 3, 2025 | Tsamtsouris | 0–1 | Papaioannou | Round 2: Tsamtsouris, Efthymios - Papaioannou, Dimitrios | Neo-Grünfeld Defense: Classical Variation, Polgar Variation | |
| Jan 2, 2025 | Papaioannou | 1–0 | Keramaros | Round 1: Papaioannou, Dimitrios - Keramaros, Vasileios | English Opening: Agincourt Defense | |
| Aug 23, 2024 | Papaioannou | 0–1 | Zielonka | EYCC 2024 - O16 | Sicilian Defense: Taimanov Variation | |
| Aug 22, 2024 | Lavrencic | 0–1 | Papaioannou | EYCC 2024 - O16 | Italian Game: Classical Variation, Giuoco Pianissimo | |
| Jul 10, 2024 | Papaioannou | 1–0 | Kyriakidis | Greek League 2024 | Ruy Lopez: Cozio Defense | |
| Jul 9, 2024 | Stathatos | ½–½ | Papaioannou | Greek League 2024 | Nimzowitsch Defense: Williams Variation | |
| Jul 8, 2024 | Papaioannou | 0–1 | Gkavardinas | Greek League 2024 | English Opening: Agincourt Defense | |
| Jul 7, 2024 | Tsarsitalidis | 0–1 | Papaioannou | Greek League 2024 | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Jul 6, 2024 | Papaioannou | 1–0 | Tagkaloglou | Greek League 2024 | French Defense: Steinitz Variation, Boleslavsky Variation | |
| Jul 5, 2024 | Armaos | ½–½ | Papaioannou | Greek League 2024 | Queen's Pawn Game: Modern Defense | |
| Jul 4, 2024 | Papaioannou | 1–0 | Skaraki | Greek League 2024 | Sicilian Defense: Delayed Alapin Variation, with e6 | |
| Jun 28, 2024 | Chalkias | 0–1 | Papaioannou | Round 9: Chalkias, Michail Panagiotis - Papaioannou, Dimitrios | ? | |
| Jun 27, 2024 | Papaioannou | 0–1 | Boulamatsis | Round 8: Papaioannou, Dimitrios - Boulamatsis, Konstantinos I | English Opening: King's English Variation, Reversed Sicilian | |
| Jun 26, 2024 | Papaioannou | 1–0 | Triantafyllakis | Round 7: Papaioannou, Dimitrios - Triantafyllakis, Dimitrios | Sicilian Defense: Closed | |
| Jun 25, 2024 | Antonioudakis | ½–½ | Papaioannou | Round 5: Antonioudakis, Georgios - Papaioannou, Dimitrios | Four Knights Game: Spanish Variation | |
| Jun 24, 2024 | Papaioannou | 1–0 | Giannoulis | Round 4: Papaioannou, Dimitrios - Giannoulis, Grigorios | Sicilian Defense: Löwenthal Variation | |
| Jun 23, 2024 | Tampakis | 0–1 | Papaioannou | Round 3: Tampakis, Vasileios - Papaioannou, Dimitrios | Sicilian Defense: Dragon Variation, Classical Variation | |
| Jun 21, 2024 | Kassios | 1–0 | Papaioannou | Round 6: Kassios, Dimitrios - Papaioannou, Dimitrios | Ruy Lopez: Morphy Defense, Neo-Arkhangelsk Variation | |
| Jun 21, 2024 | Papaioannou | ½–½ | Moysidis | Round 2: Papaioannou, Dimitrios - Moysidis, Anastasios | Sicilian Defense: Najdorf Variation, Lipnitsky Attack | |
| Jun 21, 2024 | Nakitsas | 0–1 | Papaioannou | Round 1: Nakitsas, Stergios - Papaioannou, Dimitrios | Sicilian Defense: Lasker-Pelikan Variation, Sveshnikov Variation, Chelyabinsk Variation | |
| Jul 31, 2024 | Saravanan | 1–0 | Papaioannou | Round 4: Saravanan, V. - Papaioannou, Dimitrios | King's Indian Defense: Petrosian Variation, Stein Defense | |
| Aug 17, 2022 | Magalakis | 0–1 | Papaioannou | National Greek Team Championship | English Opening: Anglo-Indian Defense, King's Indian Formation | |
| Aug 16, 2022 | Spyropoulos | ½–½ | Papaioannou | National Greek Team Championship | Torre Attack: Fianchetto Defense | |
| Aug 15, 2022 | Stefanou | 0–1 | Papaioannou | National Greek Team Championship | King's Indian Defense: Semi-Averbakh System | |
| Aug 13, 2022 | Papaioannou | 1–0 | Tragoudaras | National Greek Team Championship | King's Indian Defense: Kramer Variation | |
| Aug 13, 2022 | Giannoulis | ½–½ | Papaioannou | National Greek Team Championship | Sicilian Defense: Richter-Rauzer Variation, Modern Variation | |
| Jun 25, 2022 | Papaioannou | 0–1 | Martic | Silver Lake Open | Ruy Lopez: Closed | |
| Jun 24, 2022 | Arias Gaviria | 1–0 | Papaioannou | Silver Lake Open | Queen's Gambit Declined: Vienna Variation, Quiet Variation | |
| Jun 23, 2022 | Papaioannou | 0–1 | Krstulovic | Silver Lake Open | Caro-Kann Defense: Advance Variation, Botvinnik-Carls Defense | |
| Jun 22, 2022 | Govedarica | * | Papaioannou | Silver Lake Open | Richter-Veresov Attack | |
| Jun 20, 2022 | Saurabh Anand | 0–1 | Papaioannou | Silver Lake Open | Sicilian Defense: Four Knights Variation, Exchange Variation | |
| Jun 19, 2022 | Mohammad Nubairshah Shaikh | 1–0 | Papaioannou | Silver Lake Open | English Opening: Anglo-Indian Defense, King's Indian Formation | |
| Sep 12, 2021 | Garoufalidis | 0–1 | Papaioannou | Greek Team Championship | French Defense: Exchange Variation | |
| Sep 11, 2021 | Papaioannou | 0–1 | Georgiadis | Greek Team Championship | English Opening: Agincourt Defense | |
| Sep 10, 2021 | Terzakis | 0–1 | Papaioannou | Greek Team Championship | Zukertort Opening: Sicilian Invitation | |
| Sep 9, 2021 | Papaioannou | 1–0 | Mousliadis | Greek Team Championship | Alekhine Defense | |
| Sep 8, 2021 | Papaioannou | 1–0 | Sarantou | Greek Team Championship | French Defense: Chigorin Variation | |
| Sep 7, 2021 | Gkavardinas | 0–1 | Papaioannou | Greek Team Championship | Sicilian Defense: Four Knights Variation | |
| Jul 29, 2021 | Papaioannou | * | Rozman | 14th Paleochora International Tournament | ? | |
| Jul 27, 2021 | Papaioannou | * | Kyparissopoulos | 13th International Tournament of Paleochora | ? | |
| Jul 26, 2021 | Konstantinomanolakis | * | Papaioannou | 14th Paleochora International Tournament | ? | |
| Jul 26, 2021 | Konstantinomanolakis | * | Papaioannou | 13th International Tournament of Paleochora | ? | |
| Jul 24, 2021 | Papaioannou | 1–0 | De Vleeschauwer | 14th Paleochora International Chess Tournament 2021 | ? | |
| Jul 24, 2021 | Yankelevich | * | Papaioannou | 13th International Tournament of Paleochora | ? | |
| — | Krastev | * | Papaioannou | Secondo turno: Krastev, Alexander - Papaioannou, Dimitrios | Ruy Lopez: Morphy Defense, Tarrasch Variation | |
| — | Krastev | * | Papaioannou | Secondo turno: Krastev, Alexander - Papaioannou, Dimitrios | Indian Defense: Przepiorka Variation | |