| Jul 4, 2026 | Dittmar | 1–0 | Kapfer | Round 9: Dittmar, Peter - Kapfer, Thomas | King's Indian Defense: Steiner Attack | |
| Jul 3, 2026 | Meertens | 0–1 | Dittmar | Round 8: Meertens, Martin - Dittmar, Peter | Caro-Kann Defense: Tartakower Variation | |
| Jul 2, 2026 | Dittmar | 1–0 | Nebel | Round 7: Dittmar, Peter - Nebel, Uwe | Nimzo-Indian Defense: Kmoch Variation | |
| Jul 1, 2026 | Ahlvers | 1–0 | Dittmar | Round 6: Ahlvers, Ullrich - Dittmar, Peter | Nimzo-Indian Defense: Normal Variation | |
| Jun 30, 2026 | Dittmar | ½–½ | Eichner | Round 5: Dittmar, Peter - Eichner, Christian | Grünfeld Defense: Stockholm Variation | |
| Jun 29, 2026 | Scharrer | ½–½ | Dittmar | Round 4: Scharrer, Udo - Dittmar, Peter | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Jun 28, 2026 | Dittmar | 1–0 | Schneider | Round 3: Dittmar, Peter - Schneider, Walter | Benoni Defense: King's Pawn Line | |
| Jun 27, 2026 | Graf | ½–½ | Dittmar | Round 2: Graf, Peter - Dittmar, Peter | Caro-Kann Defense: Apocalypse Attack | |
| Jun 26, 2026 | Dittmar | 1–0 | Alter | Round 1: Dittmar, Peter - Alter, Alexander | Slav Defense | |
| Oct 12, 2025 | Dittmar | ½–½ | Fuochi | Round 9: Dittmar, Peter - Fuochi, Tommaso | Dutch Defense: Rubinstein Variation | |
| Oct 11, 2025 | Soham Dey | 0–1 | Dittmar | Round 8: Soham Dey - Dittmar, Peter | Caro-Kann Defense: Advance Variation | |
| Oct 10, 2025 | Dittmar | ½–½ | Wiesmann | Round 7: Dittmar, Peter - Wiesmann, Dominique | Pirc Defense: Classical Variation, Quiet System | |
| Oct 9, 2025 | Rutkowski | ½–½ | Dittmar | Round 6: Rutkowski, Feliks - Dittmar, Peter | Caro-Kann Defense: Exchange Variation | |
| Oct 9, 2025 | Dittmar | ½–½ | Zucchelli | Round 5: Dittmar, Peter - Zucchelli, Massimo | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Oct 7, 2025 | Bellincampi | ½–½ | Dittmar | Round 4: Bellincampi, Stefano - Dittmar, Peter | French Defense: Tarrasch Variation, Open System, Main Line | |
| Oct 6, 2025 | Dittmar | 1–0 | Ottaviani | Round 3: Dittmar, Peter - Ottaviani, Gianluca | Benoni Defense: King's Pawn Line, with Bg5 | |
| Oct 5, 2025 | Garlant | 0–1 | Dittmar | Round 2: Garlant, Carlo - Dittmar, Peter | Indian Defense: Knights Variation | |
| Oct 5, 2025 | Dittmar | ½–½ | Giuriato | Round 1: Dittmar, Peter - Giuriato, Sergio | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Oct 13, 2024 | Dittmar | ½–½ | Cazzaniga | 46th International Chess Open Citta di Arco - A | English Opening: Symmetrical Variation, Duchamp Variation | |
| Oct 12, 2024 | Cardarelli | ½–½ | Dittmar | 46th International Chess Open Citta di Arco - A | Indian Defense: Anti-Nimzo-Indian | |
| Oct 11, 2024 | Dittmar | 1–0 | Lombardo | 46th International Chess Open Citta di Arco - A | Benoni Defense: King's Pawn Line | |
| Oct 10, 2024 | Malli | ½–½ | Dittmar | 46th International Chess Open Citta di Arco - A | English Opening: Agincourt Defense | |
| Oct 9, 2024 | Dittmar | 1–0 | Nanni | 46th International Chess Open Citta di Arco - A | English Opening: King's English Variation, Two Knights Variation, Reversed Dragon | |
| Oct 8, 2024 | Dittmar | 0–1 | Buglisi | 46th International Chess Open Citta di Arco - A | English Opening: Anglo-Indian Defense, Queen's Knight Variation | |
| Oct 7, 2024 | Boder | 1–0 | Dittmar | 46th International Chess Open Citta di Arco - A | French Defense: Tarrasch Variation, Open System, Main Line | |
| Oct 6, 2024 | Dittmar | 1–0 | De Reymaeker | 46th International Chess Open Citta di Arco - A | English Opening: King's English Variation, Taimanov Variation | |
| Oct 5, 2024 | Bangerter | 0–1 | Dittmar | 46th International Chess Open Citta di Arco - A | Indian Defense: London System | |