Stadium: Court 3 Round: 44 Ground: Hardcourt outdoor
| ITF M25 Nonthaburi | 2019/05/28 05:50 | Rio Noguchi v Krittin Koaykul | 6-3,6-0 |
| ITF M25 Nonthaburi | 2019/05/20 06:55 | Alexander Crnokrak v Krittin Koaykul | 6-1,6-4 |
| ITF M15 Anning | 2019/01/14 01:30 | Kazuma Kawachi v Krittin Koaykul | 7-6,6-2 |
| ITF M15 Anning | 2018/12/31 01:30 | Krittin Koaykul v Francesco Bessire | 3-6,2-6 |
| ITF Thailand F9 | 2018/11/10 05:00 | Krittin Koaykul v Chayanon Kaewsuto | 2-6,6-1,3-6 |
| ITF Thailand F8 | 2018/11/03 02:00 | Phongsapak Kerdlaphee v Krittin Koaykul | 6-2,6-4 |
| ITF Thailand F7 | 2018/10/28 03:00 | Krittin Koaykul v Siddharth Vishwakarma | 2-6,5-7 |
| ITF Thailand F7 | 2018/10/27 02:00 | Michael Mathayomchand v Krittin Koaykul | 3-6,5-7 |