Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF M25 Decatur | 2021/08/03 16:45 | Montsi, Siphosothando v Ezekiel Clark | 3-6,6-2,15-13 |
| ITF M25 Decatur | 2021/08/02 15:00 | Brymer, Gage v Montsi, Siphosothando | 6-2,2-6,7-10 |
| ITF M25 Champaign | 2021/07/29 18:45 | Peck, Joshua v Montsi, Siphosothando | 6-3,6-7,6-4 |
| ITF M25 Champaign | 2021/07/28 19:15 | Montsi, Siphosothando v Tristan Schoolkate | 6-4,6-4 |
| ITF M15 Edwardsville | 2021/07/21 18:50 | Montsi, Siphosothando v Alexander Bernard | 6-0,5-7,6-3 |
| ITF M15 Edwardsville | 2021/07/20 14:00 | Perez, Alfredo v Montsi, Siphosothando | 6-2,4-6,5-10 |
| ITF M15 Edwardsville | 2021/07/19 15:00 | Ellefsen, Nils v Montsi, Siphosothando | 2-6,2-6 |
| ITF M15 Champaign | 2021/06/24 15:00 | Pervolarakis, Michail v Montsi, Siphosothando | 4-6,6-3,6-4 |
| ATP - Los Cabos | 2021/07/19 00:00 | Ernesto Escobedo v Alex Rybakov | 6-2,7-6 |
| ATP - Los Cabos | 2021/07/18 02:40 | Brymer, Gage v Alex Rybakov | 3-6,4-6 |
| ITF M25 Klosters | 2021/06/23 07:00 | Alex Rybakov v Leandro Riedi | 6-3,6-7,2-6 |
| Prostejov, Czech Republic | 2021/06/15 11:05 | Blaz Rola v Alex Rybakov | 6-1,7-5 |
| Prostejov, Czech Republic | 2021/06/14 08:30 | Alex Rybakov v Vanneste, Jeroen | 7-6,7-6 |
| Prostejov, Czech Republic | 2021/06/13 09:00 | Ignatik, Uladzimir v Alex Rybakov | 4-6,5-7 |
| ITF M15 Skopje | 2021/06/03 09:30 | Ryan Nijboer v Alex Rybakov | 2-6,7-6,6-4 |
| ITF M15 Skopje | 2021/06/02 08:00 | Ivanovski, Kalin v Alex Rybakov | 2-6,2-6 |