24 games in the PremovedPrep archive. Games as White.
| White | Black | Result | ECO | Event | Date |
|---|---|---|---|---|---|
| Kostowski, Ireneus, Dr. | Solski, Maksymilian | 0-1 | D01 | 62. Miedzynarodowy Festiwal Szachowy im. Akiby Rubinsteina - OPEN C | 2026-08-21 |
| Kostowski, Ireneus, Dr. | Rybka, Tatiana | 1/2-1/2 | D00 | 62. Miedzynarodowy Festiwal Szachowy im. Akiby Rubinsteina - OPEN C | 2026-08-19 |
| Kostowski, Ireneus, Dr. | Brudzynski, Wojciech | 0-1 | A46 | 62. Miedzynarodowy Festiwal Szachowy im. Akiby Rubinsteina - OPEN C | 2026-08-17 |
| Kostowski, Ireneus, Dr. | Stawecki, Bartlomiej | 1-0 | D00 | 62. Miedzynarodowy Festiwal Szachowy im. Akiby Rubinsteina - OPEN C | 2026-08-15 |
| Kostowski, Ireneus, Dr. | Demiroers, Emre | 1-0 | A45 | Round 1: Kostowski, Ireneus, Dr. - Demiroers, Emre | 2024-11-22 |
| Kostowski, Ireneus, Dr. | Arp, Piotr Alexander | 0-1 | B08 | Round 1: Kostowski, Ireneus, Dr. - Arp, Piotr Alexander | 2024-08-01 |
| Dr. Ireneus Kostowski | Wolfgang Fink | 0-1 | D00 | Round 5: Dr. Ireneus Kostowski - Wolfgang Fink | 2024-01-28 |
| Dr. Ireneus Kostowski | Stefan Donecker | 1-0 | D00 | Round 3: Ireneus, Dr. Kostowski - Stefan Donecker | 2024-01-27 |
| Ireneus, Dr. Kostowski | Michael Stenzel | 1-0 | A45 | Round 1: Ireneus, Dr. Kostowski - Michael Stenzel | 2024-01-26 |
| Kostowski, Ireneus, Dr. | Ratajek, Krzysztof | 0-1 | A45 | Rubinstein Chess Festival 2025 - OPEN B | |
| Kostowski, Ireneus, Dr. | Soszka, Szymon | 1/2-1/2 | A45 | Rubinstein Chess Festival 2025 - OPEN B | |
| Kostowski, Ireneus, Dr. | Komendecki, Grzegorz | 1-0 | D00 | Rubinstein Chess Festival 2025 - OPEN B | |
| Kostowski, Ireneus, Dr. | Szwed, Karol | 1-0 | D01 | Rubinstein Chess Festival 2025 - OPEN B | |
| Kostowski, Ireneus, Dr. | Trybus, Dominika | 0-1 | D00 | Rubinstein Chess Festival 2025 - OPEN B |