| Apr 6, 2026 | Hiermann | * | Volkov | Round 8: Hiermann, Dietmar - Volkov, Mykyta | ? | |
| Apr 4, 2026 | Ten Hertog | 1–0 | Hiermann | Round 5: Ten Hertog, Hugo - Hiermann, Dietmar | ? | |
| Apr 3, 2026 | Gschnitzer | 1–0 | Hiermann | Round 3: Gschnitzer, Adrian - Hiermann, Dietmar | ? | |
| Apr 3, 2026 | Aravindh | 1–0 | Hiermann | Round 1: Aravindh, Chithambaram VR. - Hiermann, Dietmar | ? | |
| Apr 6, 2025 | Roessler | 0–1 | Hiermann | Round 11: Roessler, Felix - Hiermann, Dietmar | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Apr 4, 2025 | Hatzl | 1–0 | Hiermann | Round 9: Hatzl, Johannes - Hiermann, Dietmar | Italian Game: Classical Variation, Greco Gambit, Anderssen Variation | |
| Aug 22, 2021 | Neurauter | * | Hiermann | Innsbruck Festival | ? | |
| Aug 22, 2021 | Neurauter | * | Hiermann | Innsbruck Festival | ? | |
| Jul 9, 2021 | Hiermann | 0–1 | Daroczi | České Budějovice Open | A | French Defense: Tarrasch Variation, Guimard Defense | |
| Jul 8, 2021 | Bartos | ½–½ | Hiermann | České Budějovice Open | A | Queen's Gambit Declined: Three Knights Variation | |
| Jul 6, 2021 | Placer | ½–½ | Hiermann | České Budějovice Open | A | Scotch Game: Mieses Variation | |
| Jul 5, 2021 | Hiermann | ½–½ | Jires | České Budějovice Open | A | Italian Game: Two Knights Defense, Modern Bishop's Opening | |
| Jul 3, 2021 | Hiermann | 0–1 | Havelka | České Budějovice Open | A | Sicilian Defense: Delayed Alapin Variation, with d6 | |
| Jul 2, 2021 | Malinovsky | 0–1 | Hiermann | České Budějovice Open | A | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Jul 1, 2021 | Hiermann | 1–0 | Balint | České Budějovice Open | A | Italian Game: Two Knights Defense, Modern Bishop's Opening | |
| Jun 6, 2021 | Hiermann | 1–0 | Soelkner | Austrian Blitz Championship | ? | |
| Jun 6, 2021 | Hiermann | 0–1 | Perhinig | Austrian Blitz Championship | French Defense: Tarrasch Variation, Closed Variation, Main Line | |
| Jun 6, 2021 | Berger | ½–½ | Hiermann | Austrian Blitz Championship | Queen's Gambit Declined: Harrwitz Attack, Fianchetto Defense | |
| Jun 6, 2021 | Weichhart | 0–1 | Hiermann | Austrian Blitz Championship | ? | |
| Jun 6, 2021 | Goessler | 0–1 | Hiermann | Austrian Blitz Championship | ? | |
| Jun 5, 2021 | Hiermann | 1–0 | Miazhynski | Austrian Rapid Championship | Caro-Kann Defense: Exchange Variation | |
| Jun 5, 2021 | Hiermann | 1–0 | Trippold | Austrian Rapid Championship | French Defense: Tarrasch Variation, Open System | |
| Jun 5, 2021 | Hiermann | 1–0 | Nolz | Austrian Rapid Championship | Sicilian Defense: Delayed Alapin Variation, with d6 | |
| Jun 5, 2021 | Teuschler | ½–½ | Hiermann | Austrian Rapid Championship | Queen's Pawn Game: Accelerated London System | |
| Jun 5, 2021 | Danner | ½–½ | Hiermann | Austrian Rapid Championship | Queen's Gambit Declined: Semi-Tarrasch Defense, Pillsbury Variation | |
| Jun 5, 2021 | Schreiner | 1–0 | Hiermann | Austrian Rapid Championship | Catalan Opening: Closed | |