| 28 ago 2026 | Kazantzoglou, Stefanos 2163 | Gkikas, Hristos 2002 | 1-0 | B13 Defensa Caro-Kann: Exchange Variation | 12th Greek Open Individual Blitz Championship 2026 | 46 | Ver |
| 28 ago 2026 | Sidiropoulos, Nikolaos K. 2007 | Kazantzoglou, Stefanos 2163 | 1-0 | A13 Apertura Inglesa: Romanishin Gambit | 12th Greek Open Individual Blitz Championship 2026 | 52 | Ver |
| 28 ago 2026 | Kazantzoglou, Stefanos 2163 | Krallis, Christos 2427 | 0-1 | D77 Defensa Neogrünfeld: Classical Variation, Polgar Variation | 12th Greek Open Individual Blitz Championship 2026 | 38 | Ver |
| 24 jul 2026 | Sochacki, Christophe 2487 | Kazantzoglou, Stefanos 2345 | 0-1 | B90 Defensa Siciliana: Najdorf Variation | 19th Paleochora International Tournament 2026 | 41 | Ver |
| 23 jul 2026 | Kazantzoglou, Stefanos 2345 | Plat, Vojtech 2491 | ½-½ | C41 Defensa Philidor: Lion Variation | 19th Paleochora International Tournament 2026 | 44 | Ver |
| 22 jul 2026 | Kazantzoglou, Stefanos 2345 | Koudounis, Vasileios 2223 | 1-0 | A07 Ataque Indio de Rey | 19th Paleochora International Tournament 2026 | 51 | Ver |
| 21 jul 2026 | Khachatryan, Anna 2193 | Kazantzoglou, Stefanos 2345 | ½-½ | D37 Gambito de Dama rehusado: Harrwitz Attack, Fianchetto Defense | 19th Paleochora International Tournament 2026 | 63 | Ver |
| 16 jul 2026 | Mihopoulos, Konstantinos 2015 | Kazantzoglou, Stefanos 2228 | 1-0 | A00 Apertura Húngara | Other events in Greek Youth U20 Individual Championships 2026 | Team Blitz 3x3 | 31 | Ver |
| 16 jul 2026 | Kazantzoglou, Stefanos 2228 | Mylonakis, Ioannis 2019 | 0-1 | A11 Apertura Réti: Anglo-Slav Variation, with g3 | Other events in Greek Youth U20 Individual Championships 2026 | Team Blitz 3x3 | 37 | Ver |
| 12 jul 2026 | Kazantzoglou, Stefanos 2228 | Vassis, Michail 2433 | 0-1 | C00 Defensa Francesa: St. George Defense | Other events in Greek Youth U20 Individual Championships 2026 | Team Blitz 3x3 | 26 | Ver |
| 10 jul 2026 | Banikas, Hristos 2545 | Kazantzoglou, Stefanos 2345 | 1-0 | A15 Apertura Inglesa: Anglo-Indian Defense, King's Knight Variation | 53rd Greek Team Championship 2026 | 60 | Ver |
| 10 jul 2026 | Kazantzoglou, Stefanos 2345 | Tsaknakis, Zisis 2292 | ½-½ | A14 Apertura Inglesa: Agincourt Defense, Neo-Catalan Declined | 53rd Greek Team Championship 2026 | 40 | Ver |
| 8 jul 2026 | Krallis, Christos 2424 | Kazantzoglou, Stefanos 2345 | 0-1 | A07 Ataque Indio de Rey: Keres Variation | 53rd Greek Team Championship 2026 | 37 | Ver |
| 7 jul 2026 | Kazantzoglou, Stefanos 2345 | Nikolaidis, Ioannis 2449 | 0-1 | C90 Apertura Española (Ruy López): Closed, Pilnik Variation | 53rd Greek Team Championship 2026 | 42 | Ver |
| 6 jul 2026 | Kazantzoglou, Stefanos 2345 | Dimitrov, Atanas 2245 | 1-0 | C41 Defensa Philidor: Lion Variation | 53rd Greek Team Championship 2026 | 46 | Ver |
| 6 jul 2026 | Kazantzoglou, Stefanos 2345 | Stefanou, Dimitrios 2358 | 1-0 | B31 Defensa Siciliana: Nyezhmetdinov-Rossolimo Attack, Fianchetto Variation | 53rd Greek Team Championship 2026 | 60 | Ver |
| 3 jul 2026 | Kazantzoglou, Stefanos 2345 | Stefanou, Dimitrios 2358 | 1-0 | C77 Apertura Española (Ruy López): Morphy Defense, Anderssen Variation | Greek Chess Cup F4 | 60 | Ver |
| 2 jul 2026 | Kazantzoglou, Stefanos 2345 | Kourkoulos-Arditis, Stamatis 2570 | 0-1 | E62 Defensa India de Rey: Fianchetto Variation, Larsen Defense | Greek Chess Cup F4 | 33 | Ver |
| 26 jun 2026 | Imomkuzieva, Nilufarkhon 2235 | Kazantzoglou, Stefanos 2312 | ½-½ | B53 Defensa Siciliana: Chekhover Variation | FIDE World Youth Chess Championships 2026 | O18 | 116 | Ver |
| 25 jun 2026 | Kazantzoglou, Stefanos 2312 | Bazilius, Augustinas 2240 | ½-½ | C02 Defensa Francesa: Advance Variation, Euwe Variation | FIDE World Youth Chess Championships 2026 | O18 | 60 | Ver |