Stadium: Court 10 Round: 44 Ground: Hardcourt outdoor
| ITF - M15 Cancún | 2021/09/30 14:30 | Christian Langmo v Seita Watanabe | 6-2,6-4 |
| ITF - M15 Cancún | 2021/09/28 17:00 | Alejandro Mendoza v Seita Watanabe | 6-7,0-6 |
| ITF - M15 Cancún | 2021/09/21 14:00 | Seita Watanabe v Leonardo Civita-Telles | 3-6,6-4,5-7 |
| ITF M15 Káhira | 2021/09/09 08:00 | Seita Watanabe v Maxime Mora | 5-7,2-6 |
| ITF M15 Káhira | 2021/09/08 08:00 | Seita Watanabe v Elbert Barr | 6-0,6-0 |
| ITF M15 Káhira | 2021/09/01 09:50 | Fares Zakaria v Seita Watanabe | 6-2,7-6 |
| ITF M15 Monastir | 2021/08/24 07:30 | Seita Watanabe v Kai Lemstra | 1-6,1-6 |
| ITF M15 Monastir | 2021/08/23 09:00 | Seita Watanabe v Samir Hamza Reguig | 6-0,6-0 |
| ITF M15 - Antalya | 2021/06/14 09:20 | Fernando A. Z. Cantillana v Ignacio Carou | 4-6,3-6 |
| ITF M15 - Antalya | 2021/06/13 07:30 | Adil Karimov v Fernando A. Z. Cantillana | 2-6,3-6 |
| ITF M15 - Antalya | 2021/06/07 07:00 | Fernando A. Z. Cantillana v Vladislav Ivanov | 1-6,0-6 |
| ITF M15 - Antalya | 2021/06/06 07:30 | Gokberk Saritas v Fernando A. Z. Cantillana | 4-6,2-6 |
| ITF M15 - Antalya | 2021/05/31 09:30 | Fernando A. Z. Cantillana v Francisco Llanes | 0-6,1-6 |
| ITF M15 - Antalya | 2021/05/16 07:00 | Fernando A. Z. Cantillana v Miguel Fernando Pereira | 2-6,4-6 |
| ITF Chile F8 | 2016/12/17 14:30 | Fernando A. Z. Cantillana v Cristopher Kohl | 2-6,2-6 |