| Nov 1, 2025 | Hartung-Nielsen | 1–0 | Fradkin | Round 11: Hartung-Nielsen, Jens - Fradkin, Benjamin | Caro-Kann Defense: Panov Attack | |
| Oct 31, 2025 | Theon | 1–0 | Hartung-Nielsen | Round 10: Theon, Pierre - Hartung-Nielsen, Jens | Sicilian Defense: Hyperaccelerated Fianchetto | |
| Oct 30, 2025 | Hartung-Nielsen | 1–0 | Gosch | Round 9: Hartung-Nielsen, Jens - Gosch, Manfred | Pirc Defense: Byrne Variation | |
| Oct 29, 2025 | Stoychev | 1–0 | Hartung-Nielsen | Round 8: Stoychev, Ognian - Hartung-Nielsen, Jens | Tarrasch Defense: Dubov Tarrasch | |
| Oct 28, 2025 | Hartung-Nielsen | ½–½ | Baasanjav | Round 7: Hartung-Nielsen, Jens - Baasanjav, Mijid | Queen's Pawn Game: Colle System | |
| Oct 26, 2025 | Ilyes | 0–1 | Hartung-Nielsen | Round 6: Ilyes, Peter - Hartung-Nielsen, Jens | Queen's Pawn Game: Stonewall Attack | |
| Oct 25, 2025 | Hartung-Nielsen | ½–½ | Moise | Round 5: Hartung-Nielsen, Jens - Moise, Octavian-Mirel | Sicilian Defense: Lasker-Pelikan Variation, Sveshnikov Variation | |
| Oct 24, 2025 | Canonne | 0–1 | Hartung-Nielsen | Round 4: Canonne, Antoine - Hartung-Nielsen, Jens | Sicilian Defense: Grand Prix Attack | |
| Oct 23, 2025 | Hartung-Nielsen | 0–1 | Bekentayev | Round 3: Hartung-Nielsen, Jens - Bekentayev, Uran | Sicilian Defense: Dragon Variation, Yugoslav Attack, Modern Line | |
| Oct 22, 2025 | Choong | 0–1 | Hartung-Nielsen | Round 2: Choong, Liong-On Mark - Hartung-Nielsen, Jens | Tarrasch Defense: Classical Variation | |
| Oct 21, 2025 | Hartung-Nielsen | 0–1 | Hulse | Round 1: Hartung-Nielsen, Jens - Hulse, Brian | Caro-Kann Defense: Karpov Variation | |
| Feb 14, 2025 | Hartung-Nielsen | 1–0 | Lauritsen | senior-dm | English Opening: King's English Variation, Taimanov Variation | |
| Feb 13, 2025 | Pedersen | ½–½ | Hartung-Nielsen | 65+ group | Tarrasch Defense: Two Knights Variation | |
| Feb 12, 2025 | Hartung-Nielsen | 1–0 | Nielsen | 65+ group | Slav Defense: Quiet Variation, Pin Defense | |
| Feb 11, 2025 | Teimer | ½–½ | Hartung-Nielsen | 65+ group | Catalan Opening: Closed | |
| Feb 10, 2025 | Hartung-Nielsen | ½–½ | Petersen | 65+ group | Rapport-Jobava System | |
| Feb 9, 2025 | Skovgaard | ½–½ | Hartung-Nielsen | 65+ group | Sicilian Defense: French Variation, Normal | |
| Feb 8, 2025 | Hartung-Nielsen | 1–0 | Olsen | 65 + group | Queen's Pawn Game | |
| Oct 26, 2023 | Hartung-Nielsen | * | Algars | 65+ World Senior Championship | ? | |
| Oct 25, 2023 | Carlsten | * | Hartung-Nielsen | 65+ World Senior Championship | ? | |
