Stadium: Cancha 5 Round: 25 Ground: Clay
| Challenger - Campinas | 2018/10/03 00:05 | Guilherme Clezar v Cristian Garin | 7-6,6-7,4-6 |
| US Open | 2018/08/23 19:40 | Lorenzo Sonego v Guilherme Clezar | 7-5,5-7,6-3 |
| US Open | 2018/08/22 22:40 | Ricardo Ojeda Lara v Guilherme Clezar | 4-6,3-6 |
| Challenger - Cordenons | 2018/08/18 15:00 | Mate Valkusz v Guilherme Clezar | 6-2,6-4 |
| Challenger - Cordenons | 2018/08/17 12:30 | Guilherme Clezar v Facundo Bagnis | 6-4,4-6,6-2 |
| Challenger - Cordenons | 2018/08/15 13:10 | Guilherme Clezar v Pedro Cachin | 6-2,6-4 |
| Challenger - Cordenons | 2018/08/13 17:00 | Guilherme Clezar v Riccardo Balzerani | 6-2,7-5 |
| Challenger Pullach | 2018/08/07 16:35 | Mats Moraing v Guilherme Clezar | 6-2,3-6,6-3 |
| Challenger - Banja Luka | 2018/09/11 08:00 | Kento Tagashira v Cristian Garin | 0-6,1-6 |
| ITF Ecuador F2 Qual | 2018/07/29 18:00 | Kento Tagashira v Juan R Bisono | 0-6,2-6 |
| ITF Ecuador F1 | 2018/07/24 20:35 | Kento Tagashira v Emilio Gomez | 1-6,1-6 |
| ITF China F11 Qual | 2018/07/14 01:00 | Owen Lu v Kento Tagashira | 6-3,6-2 |
| ITF Guam F1 | 2018/06/17 01:00 | Jeremy Sonkin v Kento Tagashira | 6-1,6-1 |
| ITF Japan F8 | 2018/06/09 01:00 | Takuya Kumasaka v Kento Tagashira | 7-6,6-0 |
| ITF China F8 | 2018/06/05 03:40 | Wishaya Trongcharoenchaikul v Kento Tagashira | 6-1,6-2 |
| ITF China F8 Qual | 2018/06/03 02:00 | Lewei Cai v Kento Tagashira | 1-6,2-6 |