Stadium: Center Court Round: 25 Ground: Clay
| Challenger Potchefstroom | 2021/02/17 10:30 | Dimitar Kuzmanov v Tristan Lamasine | 7-5,7-6 |
| Challenger Tampere Qual | 2018/07/23 08:00 | Dimitar Kuzmanov v Tristan Lamasine | 6-7,6-3,4-6 |
| Challenger Rome | 2021/04/27 08:00 | Juan Manuel Cerundolo v Tristan Lamasine | 7-5,7-5 |
| Challenger Rome | 2021/04/26 09:30 | Tristan Lamasine v Riccardo Bonadio | 6-4,6-1 |
| Challenger Rome Qual | 2021/04/25 08:00 | Tristan Lamasine v Tomas Lipovsek Puches | 6-2,6-3 |
| Challenger Rome | 2021/04/23 09:00 | Tristan Lamasine v Hugo Gaston | 2-6,6-7 |
| Challenger Rome | 2021/04/21 11:50 | Paolo Lorenzi v Tristan Lamasine | 6-4,1-6,5-7 |
| Challenger Rome | 2021/04/20 16:05 | Alex Bolt v Tristan Lamasine | 3-6,4-6 |
| Challenger Rome | 2021/04/19 08:00 | Zizou Bergs v Tristan Lamasine | 6-3,6-7,2-6 |
| Challenger Split | 2021/04/12 08:30 | Kacper Zuk v Tristan Lamasine | 7-6,6-4 |
| Challenger Zagreb | 2021/05/09 08:30 | Zhizhen Zhang v Dimitar Kuzmanov | 4-6,6-2,6-3 |
| Challenger Biella | 2021/05/05 08:00 | Dimitar Kuzmanov v Juan Pablo Varillas | 1-6,7-5,6-7 |
| Challenger Biella | 2021/05/04 08:00 | Dimitar Kuzmanov v Lorenzo Giustino | 6-3,1-6,6-3 |
| Challenger Biella | 2021/05/03 08:30 | Viktor Galovic v Dimitar Kuzmanov | 6-4,6-2 |
| Challenger Biella | 2021/05/02 12:30 | Stefano Reitano v Dimitar Kuzmanov | 6-2,2-6,2-6 |
| Challenger Oeiras | 2021/04/07 14:00 | Dimitar Kuzmanov v Ernesto Escobedo | 6-2,6-2 |
| Challenger Oeiras | 2021/04/05 12:25 | Dimitar Kuzmanov v Lucas Miedler | 6-1,6-0 |
| Challenger Zadar | 2021/03/28 10:00 | Nikola Milojevic v Dimitar Kuzmanov | 2-6,6-2,7-6 |