| Jan 4, 2026 | Myrmus | 0–1 | Costache | XXXVI Miedzynarodowy Festiwal Szachowy C | Queen's Indian Defense: Classical Variation | |
| Jan 3, 2026 | Costache | ½–½ | Wandor | XXXVI Miedzynarodowy Festiwal Szachowy CRACOVIA 2025 Grupa A | Sicilian Defense: Najdorf Variation, Adams Attack | |
| Jan 2, 2026 | Pietrzak | 1–0 | Costache | XXXVI Miedzynarodowy Festiwal Szachowy CRACOVIA 2025 Grupa A | Queen's Pawn Game: Colle System | |
| Jan 2, 2026 | Michalowski | 1–0 | Costache | XXXVI Miedzynarodowy Festiwal Szachowy CRACOVIA 2025 Grupa A | Scandinavian Defense: Modern Variation | |
| Dec 31, 2025 | Costache | 0–1 | Ernst | Open A | Scotch Game: Mieses Variation | |
| Dec 30, 2025 | Kozlowski | 0–1 | Costache | XXXVI Miedzynarodowy Festiwal Szachowy CRACOVIA 2025 Grupa A | Bogo-Indian Defense: Retreat Variation | |
| Dec 29, 2025 | Costache | 0–1 | Adamovics | XXXVI Miedzynarodowy Festiwal Szachowy CRACOVIA 2025 Grupa A | Sicilian Defense: Taimanov Variation, Bastrikov Variation, English Attack | |
| Dec 28, 2025 | Csernyik | ½–½ | Costache | XXXVI Miedzynarodowy Festiwal Szachowy CRACOVIA 2025 Grupa A | Sicilian Defense: Najdorf Variation | |
| Dec 27, 2025 | Costache | 0–1 | Shilon Rahav | Open A | Sicilian Defense: Lasker-Pelikan Variation, Sveshnikov Variation, Chelyabinsk Variation | |
| Jul 26, 2025 | Sachilaru | ½–½ | Costache | Round 1: Sachilaru, Alexandru - Costache, Andrei Eugeniu | Scandinavian Defense: Marshall Variation | |
| Jun 1, 2025 | Myagmarsuren | ½–½ | Costache | Norway Chess Open 2025 | Sicilian Defense: Najdorf Variation, Adams Attack | |
| May 31, 2025 | Costache | 1–0 | Chernetskiy | Norway Chess Open 2025 | French Defense: Classical Variation, Steinitz Variation | |
| May 30, 2025 | Elsness | 0–1 | Costache | Norway Chess Open 2025 | Scandinavian Defense: Marshall Variation | |
| May 30, 2025 | Costache | 0–1 | Charvi A | Norway Chess Open 2025 | Sicilian Defense: Najdorf Variation, Freak Attack | |
| May 29, 2025 | Costache | 1–0 | Simonsen | Norway Chess Open 2025 | Sicilian Defense: Chekhover Variation | |
| May 29, 2025 | Pang | * | Costache | Norway Chess Open 2025 | English Opening: Symmetrical Variation | |
| May 28, 2025 | Costache | * | Nechitaylo | Norway Chess Open 2025 | Sicilian Defense: Kalashnikov Variation | |
| May 27, 2025 | Swarna Nihal | 1–0 | Costache | Norway Chess Open 2025 | ? | |
| Feb 18, 2025 | Costache | 0–1 | Nastore | Round 4: Costache, Andrei Eugeniu - Nastore, Pavel-Alexandru | Sicilian Defense: Najdorf Variation, Freak Attack | |
| Feb 16, 2025 | Costache | 0–1 | Bida | Round 2: Costache, Andrei Eugeniu - Bida, Mihai-Eugen | Sicilian Defense: Najdorf Variation, Adams Attack | |
| Dec 18, 2024 | Costache | 0–1 | Naoum | XI Sunway Sitges International Chess Festival 2024 - Group A | Sicilian Defense: Dragon Variation, Classical Variation | |
| Jul 16, 2024 | Costache | 0–1 | Nedelcu | Round 2: Costache, Andrei Eugeniu - Nedelcu, Teodor-Cosmin | Sicilian Defense: Four Knights Variation | |
| Jun 15, 2024 | Riciu | * | Costache | Round 7: Riciu, Ionut - Costache, Andrei Eugeniu | London System | |
| Jun 15, 2024 | Iavorschi | * | Costache | Round 1: Iavorschi, Andrei - Costache, Andrei Eugeniu | Four Knights Game: Spanish Variation | |
| Jun 15, 2024 | Costache | 1–0 | Sabarez | Round 4: Costache, Andrei Eugeniu - Sabarez, Iulian | Sicilian Defense: French Variation, Open | |
| Jun 15, 2024 | Mogirzan Matei | * | Costache | Round 5: Mogirzan Matei - Costache, Andrei Eugeniu | Sicilian Defense: Najdorf Variation, Lipnitsky Attack | |
| Jun 15, 2024 | Costache | 1–0 | Opariuc | Round 2: Costache, Andrei Eugeniu - Opariuc, Matei | Nimzo-Indian Defense: Classical Variation | |
| Jun 15, 2024 | Costache | * | Rusu | Round 6: Costache, Andrei Eugeniu - Rusu, Lucas | English Opening: Anglo-Indian Defense, Hedgehog System | |
| Jun 15, 2024 | Codru | 0–1 | Costache | Round 3: Codru, Raul Cristian - Costache, Andrei Eugeniu | Queen's Pawn Game | |
| Apr 19, 2024 | Ilinca | 1–0 | Costache | Round 9: Ilinca, Felix-Antonio - Costache, Andrei Eugeniu | Sicilian Defense: Najdorf Variation, Freak Attack | |
| Apr 18, 2024 | Costache | ½–½ | Tanasie | Round 8: Costache, Andrei Eugeniu - Tanasie, Cosmin | Sicilian Defense: Accelerated Dragon, Maróczy Bind | |
| Apr 13, 2024 | Costache | 0–1 | Dodoi | Round 3: Costache, Andrei Eugeniu - Dodoi, Matei-Teodor | Sicilian Defense: Kan Variation, Knight Variation | |
| Oct 5, 2024 | Padurariu | 1–0 | Costache | Round 8: Padurariu, Mihai-Edward - Costache, Andrei Eugeniu | Queen's Gambit Declined: Ragozin Defense, Alekhine Variation | |
| Oct 4, 2024 | Szabo | 1–0 | Costache | Round 7: Szabo, Attila - Costache, Andrei Eugeniu | English Opening: Symmetrical Variation | |
| Oct 3, 2024 | Georgescu | 0–1 | Costache | Round 6: Georgescu, Tiberiu-Marian - Costache, Andrei Eugeniu | Indian Defense: Anti-Nimzo-Indian | |
| Oct 2, 2024 | Pisu | 1–0 | Costache | Round 5: Pisu, Robert-Daniel - Costache, Andrei Eugeniu | Sicilian Defense: Najdorf Variation, Freak Attack | |
| Oct 1, 2024 | Itkis | ½–½ | Costache | Round 4: Itkis, Boris - Costache, Andrei Eugeniu | Nimzo-Indian Defense: Normal Variation, Schlechter Defense | |
| Sep 30, 2024 | Magold | 1–0 | Costache | Round 3: Magold, Filip - Costache, Andrei Eugeniu | Sicilian Defense: Najdorf Variation | |
| Sep 29, 2024 | Popescu | ½–½ | Costache | Round 2: Popescu, Daniel-Vasilica - Costache, Andrei Eugeniu | Queen's Gambit Declined: Ragozin Defense | |
| Sep 28, 2024 | Cioara | * | Costache | Round 1: Cioara, Andrei-Nestor - Costache, Andrei Eugeniu | ? | |
| Aug 7, 2024 | Kraus | 1–0 | Costache | Round 4: Kraus, Tomas - Costache, Andrei Eugeniu | English Opening: Symmetrical Variation | |
| Jun 29, 2022 | Puia | ½–½ | Costache | FISCA Open | Semi-Slav Defense: Accelerated Move Order | |
| Jun 27, 2022 | Nicolae | ½–½ | Costache | FISCA Open | Sicilian Defense: Closed | |
| Jun 23, 2022 | Eva | * | Costache | FISCA Open | ? | |
| Jun 22, 2022 | Costache | 0–1 | Daianu | FISCA Open | Sicilian Defense: Delayed Alapin Variation, Basman-Palatnik Double Gambit | |
| — | Costache | 1–0 | Soulier | Round 4: Costache, Andrei Eugeniu - Soulier, Alfred | Sicilian Defense: Najdorf Variation, Adams Attack | |
| — | Costache | 1–0 | Canova | Round 6: Costache, Andrei Eugeniu - Canova, Luca | Scotch Game: Malaniuk Variation | |
| — | Costache | 1–0 | Paleologu | Round 8: Costache, Andrei Eugeniu - Paleologu, Vladimir | Elephant Gambit | |
| — | Valsecchi | 1–0 | Costache | Round 1: Valsecchi, Alessio - Costache, Andrei Eugeniu | English Opening: Symmetrical Variation, Ultra-Symmetrical Variation | |
| — | Hercegovac | 1–0 | Costache | Round 3: Hercegovac, Neven - Costache, Andrei Eugeniu | Scandinavian Defense: Modern Variation | |
| — | Mrudul Dehankar | 1–0 | Costache | Round 5: Mrudul Dehankar - Costache, Andrei Eugeniu | Scandinavian Defense: Modern Variation | |
| — | Apaar Saxena | 1–0 | Costache | Round 7: Apaar Saxena - Costache, Andrei Eugeniu | Indian Defense: Anti-Nimzo-Indian | |
| — | Pandey Srishti | 1–0 | Costache | Round 9: Pandey Srishti - Costache, Andrei Eugeniu | Sicilian Defense: Najdorf Variation, English Attack | |
