| Jan 26, 2024 | Leandro Perdomo | 1–0 | Mateus Costamilan Tomiello | Round 8: Leandro Perdomo - Mateus Costamilan Tomiello | Slav Defense: Geller Gambit | |
| Jan 22, 2024 | Mateus Costamilan Tomiello | 0–1 | Jose Fernando Cuenca Jimenez | Round 3: Mateus Costamilan Tomiello - Jose Fernando Cuenca Jimenez | English Opening: King's English Variation, Two Knights Variation, Smyslov System | |
| Nov 8, 2023 | Mateus Costamilan Tomiello | 0–1 | Diego Saul Rodri Flores Quillas | Round 4: Mateus Costamilan Tomiello - Diego Saul Rodri Flores Quillas | English Opening: King's English Variation, Four Knights Variation, Fianchetto Line | |
| Nov 7, 2023 | Pablo Castro Salgado | 1–0 | Mateus Costamilan Tomiello | Round 3: Pablo Castro Salgado - Mateus Costamilan Tomiello | Queen's Gambit Declined: Harrwitz Attack, Two Knights Defense, Blockade Line | |
| Nov 6, 2023 | Mateus Costamilan Tomiello | 1–0 | Kaua Marques Silva | Round 2: Mateus Costamilan Tomiello - Kaua Marques Silva | English Opening: Symmetrical Variation, Botvinnik System Reversed, with e3 | |
| Sep 21, 2023 | Mateus Costamilan Tomiello | ½–½ | Marco Delgado Romero | Round 8: Mateus Costamilan Tomiello - Marco Delgado Romero | English Opening: King's English Variation, Four Knights Variation, Fianchetto Line | |
| Sep 19, 2023 | Mateus Costamilan Tomiello | ½–½ | Matias Perez Gormaz | Round 6: Mateus Costamilan Tomiello - Matias Perez Gormaz | English Opening: King's English Variation, Four Knights Variation, Fianchetto Line, with Nb6 | |
| Sep 15, 2023 | Mateus Costamilan Tomiello | ½–½ | Cristhian Cruz | Round 2: Mateus Costamilan Tomiello - Cristhian Cruz | English Opening: Agincourt Defense, Catalan Defense Accepted | |
| Jul 15, 2023 | Mateus Costamilan Tomiello | 1–0 | Antu Amigo Quintana | Round 9: Mateus Costamilan Tomiello - Antu Amigo Quintana | Ruy Lopez: Morphy Defense | |
| Jul 15, 2023 | Nathan Felipe Filgueiras | 1–0 | Mateus Costamilan Tomiello | Round 8: Nathan Felipe Filgueiras - Mateus Costamilan Tomiello | Four Knights Game | |
| Jul 14, 2023 | Juan Sebastian Melian | 0–1 | Mateus Costamilan Tomiello | Round 7: Juan Sebastian Melian - Mateus Costamilan Tomiello | Sicilian Defense: Alapin Variation, Stoltz Attack | |
| Jul 13, 2023 | Mateus Costamilan Tomiello | 1–0 | Pablo Castro Salgado | Round 6: Mateus Costamilan Tomiello - Pablo Castro Salgado | Sicilian Defense: Taimanov Variation | |
| Jul 12, 2023 | Mateus Costamilan Tomiello | ½–½ | Lucas Costamilan Tomiello | Round 5: Mateus Costamilan Tomiello - Lucas Costamilan Tomiello | Ruy Lopez: Berlin Defense, l'Hermet Variation, Berlin Wall Defense | |
| Jul 12, 2023 | Matias Jaque Gutierrez | ½–½ | Mateus Costamilan Tomiello | Round 4: Matias Jaque Gutierrez - Mateus Costamilan Tomiello | Catalan Opening: Open Defense, Classical Line | |
| Jul 11, 2023 | Felipe Perez Rojas | 0–1 | Mateus Costamilan Tomiello | Round 3: Felipe Perez Rojas - Mateus Costamilan Tomiello | Sicilian Defense: Lasker-Pelikan Variation, Sveshnikov Variation, Chelyabinsk Variation | |
| Jan 26, 2023 | Mateus Costamilan Tomiello | 0–1 | Diego Saul Rodri Flores Quillas | Round 6: Mateus Costamilan Tomiello - Diego Saul Rodri Flores Quillas | Nimzo-Indian Defense: Reshevsky Variation | |
