| Oct 12, 2025 | McShane | 1–0 | Papaioannou | Round 7: McShane, Luke J - Papaioannou, Ioannis | Sicilian Defense: Modern Variations | |
| Oct 8, 2025 | Papaioannou | 0–1 | Indjic | Round 4: Papaioannou, Ioannis - Indjic, Aleksandar | Ruy Lopez: Morphy Defense, Anderssen Variation | |
| Oct 7, 2025 | Papaioannou | ½–½ | Demchenko | Round 3: Papaioannou, Ioannis - Demchenko, Anton | East Indian Defense | |
| Oct 5, 2025 | Hamitevici | ½–½ | Papaioannou | Round 1: Hamitevici, Vladimir - Papaioannou, Ioannis | English Opening: Agincourt Defense | |
| Jul 4, 2025 | Papaioannou | 1–0 | Giannoulakis | Round 7: Papaioannou, Ioannis - Giannoulakis, Lampros | Bogo-Indian Defense: Retreat Variation | |
| Jul 3, 2025 | Gkoumas | ½–½ | Papaioannou | Round 6: Gkoumas, Georgios - Papaioannou, Ioannis | Sicilian Defense: Najdorf Variation, Opocensky Variation | |
| Jul 3, 2025 | Papaioannou | 1–0 | Kotrotsos | Round 4: Papaioannou, Ioannis - Kotrotsos, Vasilios | Queen's Gambit Accepted: Classical Defense, Normal Line | |
| Jul 3, 2025 | Nikolaidis | ½–½ | Papaioannou | Round 3: Nikolaidis, Ioannis - Papaioannou, Ioannis | Queen's Gambit Accepted: Central Variation, Alekhine System | |
| Jul 3, 2025 | Papaioannou | ½–½ | Tsaknakis | Round 2: Papaioannou, Ioannis - Tsaknakis, Zisis | Italian Game: Giuoco Pianissimo, Italian Four Knights Variation | |
| Jul 3, 2025 | Georgiou | 0–1 | Papaioannou | Round 1: Georgiou, Kostantinos - Papaioannou, Ioannis | Indian Defense: Anti-Nimzo-Indian | |
| Jul 3, 2025 | Papaioannou | 1–0 | Kourousis | Round 5: Papaioannou, Ioannis - Kourousis, Epameinondas | Modern Defense: Geller's System | |
| Jun 8, 2025 | Pavlidis | ½–½ | Papaioannou | 43rd Hybrid Greek Cup 2025 F16 | Sicilian Defense: Najdorf Variation, Opocensky Variation | |
| Sep 22, 2024 | Papaioannou | ½–½ | Salinas Herrera | 45th FIDE Chess Olympiad | Bogo-Indian Defense: Retreat Variation | |
| Sep 21, 2024 | Papaioannou | 1–0 | Djukic | 45th FIDE Chess Olympiad | Indian Defense: London System | |
| Sep 20, 2024 | Papaioannou | ½–½ | Mamedyarov | 45th FIDE Chess Olympiad | Queen's Pawn Game: London System | |
| Sep 19, 2024 | Wong | 0–1 | Papaioannou | 45th FIDE Chess Olympiad | Bogo-Indian Defense: Grünfeld Variation | |
| Sep 16, 2024 | Druska | 0–1 | Papaioannou | 45th FIDE Chess Olympiad | Sicilian Defense: Najdorf Variation, Opocensky Variation | |
| Sep 15, 2024 | Papaioannou | 1–0 | Seeman | 45th FIDE Chess Olympiad | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Sep 14, 2024 | Preotu | ½–½ | Papaioannou | 45th FIDE Chess Olympiad | King's Indian Attack | |
| Sep 13, 2024 | Papaioannou | 1–0 | O`Gorman | 45th FIDE Chess Olympiad | Ruy Lopez: Morphy Defense, Anderssen Variation | |
| Sep 11, 2024 | Monnaatsheko | 0–1 | Papaioannou | 45th FIDE Chess Olympiad | Zukertort Opening: Nimzo-Larsen Variation | |
| Jul 9, 2024 | Papaioannou | 1–0 | Kapnisis | Greek League 2024 | Benoni Defense: Benoni-Indian Defense, Kingside Move Order | |
| Jul 8, 2024 | Papaioannou | ½–½ | Kotrotsos | Greek League 2024 | Queen's Gambit Accepted: Furman Variation | |
| Jul 7, 2024 | Tsaknakis | ½–½ | Papaioannou | Greek League 2024 | King's Indian Attack | |
| Jul 5, 2024 | Papaioannou | ½–½ | Papadopoulos | Greek League 2024 | Pseudo Queen's Indian Defense | |
| Jul 4, 2024 | Pavlidis | ½–½ | Papaioannou | Greek League 2024 | Four Knights Game: Scotch Variation Accepted | |
| Nov 18, 2023 | Papaioannou | ½–½ | Teclaf | European Team Championship | Horwitz Defense | |
| Nov 17, 2023 | Papaioannou | ½–½ | Abasov | European Team Championship | Catalan Opening: Open Defense | |
| Nov 14, 2023 | Santos Latasa | ½–½ | Papaioannou | European Team Championship | Queen's Gambit Declined: Barmen Variation | |
| Nov 13, 2023 | Papaioannou | 1–0 | Pultinevicius | European Team Championship | Caro-Kann Defense: Exchange Variation | |
| Nov 11, 2023 | Egilstoft | ½–½ | Papaioannou | European Team Championship | Sicilian Defense: Delayed Alapin Variation | |
| Aug 19, 2022 | Papaioannou | 1–0 | Koutlas | Greek Team Cup Final 8 | Queen's Gambit Declined: Modern Variation | |
| Aug 18, 2022 | Papaioannou | 1–0 | Balaskas | Greek Team Cup Final 8 | Sicilian Defense: Moscow Variation, Main Line | |
| Aug 18, 2022 | Ladopoulos | ½–½ | Papaioannou | Greek Team Cup Final 8 | Indian Defense: Knights Variation | |
| Aug 17, 2022 | Lubbe | 1–0 | Papaioannou | National Greek Team Championship | Benoni Defense | |
| Aug 16, 2022 | Papaioannou | ½–½ | Halkias | National Greek Team Championship | Ruy Lopez: Closed, Flohr System | |
| Aug 15, 2022 | Papaioannou | 1–0 | Korpa | National Greek Team Championship | Queen's Pawn Game: Torre Attack, Grünfeld Variation, Main Line | |
| Aug 14, 2022 | Pavlidis | ½–½ | Papaioannou | National Greek Team Championship | Ruy Lopez: Closed, Flohr System | |
| Aug 13, 2022 | Papaioannou | ½–½ | Kelires | National Greek Team Championship | Bogo-Indian Defense: Retreat Variation | |
| Aug 13, 2022 | Kalogeris | 0–1 | Papaioannou | National Greek Team Championship | Sicilian Defense: Najdorf Variation, Freak Attack | |
| Aug 12, 2022 | Papaioannou | 1–0 | Alexiadis | National Greek Team Championship | English Opening: Anglo-Indian Defense, King's Indian Formation | |
| Sep 12, 2021 | Papadopoulos | 0–1 | Papaioannou | Greek Team Championship | Nimzo-Indian Defense: Rubinstein System, Taimanov Variation | |
| Sep 11, 2021 | Papaioannou | 1–0 | Alexakis | Greek Team Championship | English Opening: Symmetrical Variation, Anti-Benoni Variation | |
| Sep 10, 2021 | Loutragotis | 0–1 | Papaioannou | Greek Team Championship | Italian Game: Two Knights Defense, Modern Bishop's Opening | |
| Sep 9, 2021 | Papaioannou | 1–0 | Hristodoulou | Greek Team Championship | Queen's Gambit Declined | |
| Sep 8, 2021 | Papaioannou | 1–0 | Stathopoulos | Greek Team Championship | Torre Attack: Fianchetto Defense | |
| Sep 8, 2021 | Kelires | ½–½ | Papaioannou | Greek Team Championship | Ruy Lopez: Closed, Flohr System | |
| Sep 7, 2021 | Papaioannou | 1–0 | Kapnisis | Greek Team Championship | Four Knights Game: Spanish Variation | |
