| Jan 24, 2026 | Rupasinghe | 1–0 | Horikawa | 2026 Australian Championship Under 18 years | Caro-Kann Defense: Exchange Variation | |
| Jan 22, 2026 | Gao | 1–0 | Horikawa | 2026 Australian Championship Under 18 years | Caro-Kann Defense: Advance Variation, Bayonet Attack | |
| Jan 18, 2026 | Horikawa | 0–1 | Chang | 2026 Australian Championship Under 18 years | French Defense: Exchange Variation, Monte Carlo Variation | |
| Jan 17, 2026 | Horikawa | 0–1 | Chang | 2026 Australian Championship Under 18 years | French Defense: Exchange Variation, Monte Carlo Variation | |
| Jul 27, 2025 | Ikeda | 1–0 | Horikawa | 2025 ANU Open | Catalan Opening: Closed Variation, Traditional Variation | |
| Jul 27, 2025 | Horikawa | 1–0 | Litchfield | 2025 ANU Open | Sicilian Defense: Moscow Variation | |
| Jul 26, 2025 | Tang | ½–½ | Horikawa | 2025 ANU Open | Caro-Kann Defense: Maróczy Variation | |
| Jun 6, 2025 | Wang | 1–0 | Horikawa | 2025 NSW Open | Caro-Kann Defense: Two Knights Attack | |
| Jun 6, 2025 | Horikawa | ½–½ | Nguyen | 2025 NSW Open | Scotch Game: Scotch Gambit, Göring Gambit Declined | |
| Jul 10, 2024 | Horikawa | 0–1 | Brown | Round 11: Horikawa, Masaki - Brown, Heath | Scotch Game: Scotch Gambit, Göring Gambit Declined | |
| Jul 10, 2024 | Horikawa | 1–0 | Lau | Round 9: Horikawa, Masaki - Lau, Winson | Modern Defense | |
| Jul 10, 2024 | Huynh | 0–1 | Horikawa | Round 8: Huynh, Arthur - Horikawa, Masaki | Bogo-Indian Defense: Exchange Variation | |
| Jul 10, 2024 | Solan | * | Horikawa | Round 6: Solan, Jesse - Horikawa, Masaki | ? | |
| Jul 10, 2024 | Xie | 1–0 | Horikawa | Round 5: Xie, George Wendi - Horikawa, Masaki | Richter-Veresov Attack: Richter Variation | |
| Jul 10, 2024 | Horikawa | 1–0 | Anderson | Round 4: Horikawa, Masaki - Anderson, Brendan | Scotch Game: Scotch Gambit, Göring Gambit Declined | |
| Jul 10, 2024 | Yu | 1–0 | Horikawa | Round 2: Yu, Changhao - Horikawa, Masaki | Caro-Kann Defense: Apocalypse Attack | |
| Jun 7, 2024 | Chakrabarty | 1–0 | Horikawa | Round 10: Chakrabarty, Reyaansh - Horikawa, Masaki | Caro-Kann Defense: Exchange Variation, Rubinstein Variation | |
| — | Horikawa | * | Chakrabarty | 2025 Sydney International Open Blitz | Philidor Defense: Lion Variation, Bishop Sacrifice | |
