Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF M25 Idanha-A-Nova | 2021/07/16 07:55 | Nicolas Moreno De Alboran v Joao Lucas Reis da Silva | 7-6,6-4 |
| ITF M25 Idanha-A-Nova | 2021/07/15 10:15 | Luis Faria v Joao Lucas Reis da Silva | 6-4,2-6,3-6 |
| ITF M25 Idanha-A-Nova | 2021/07/13 12:30 | Joao Lucas Reis da Silva v Yusuke Takahashi | 6-3,6-1 |
| ITF M15 Almada | 2021/07/10 08:30 | Fabio Coelho v Joao Lucas Reis da Silva | 6-3,6-4 |
| ITF M15 Almada | 2021/07/09 10:20 | Joao Lucas Reis da Silva v Diego F Flores | 6-4,7-6 |
| ITF M15 Almada | 2021/07/08 12:30 | Joao Lucas Reis da Silva v Daniel Batista | 6-2,6-3 |
| ITF M15 Almada | 2021/07/06 10:30 | Joao Lucas Reis da Silva v Kuzey Cekirge | 6-1,6-3 |
| ITF M25 The Hague | 2021/07/01 12:10 | Jelle Sels v Joao Lucas Reis da Silva | 6-3,6-3 |
| Challenger Aix en Provence | 2021/06/13 10:00 | Marek Gengel v Eduard Esteve Lobato | 0-6,1-6 |
| ITF M15 Gaiba | 2021/06/08 13:50 | Marek Gengel v Mats Rosenkranz | 6-4,5-7,1-6 |
| ITF M25 Most | 2021/05/26 09:35 | Antonin Bolardt v Marek Gengel | 7-6,6-0 |
| ITF M15 Tbilisi | 2021/05/21 06:00 | Alexander Shevchenko v Marek Gengel | 6-7,6-4,6-4 |
| ITF M15 Tbilisi | 2021/05/20 09:40 | Aidan Mayo v Marek Gengel | 3-6,2-6 |
| ITF M15 Tbilisi | 2021/05/18 07:00 | Marat Deviatiarov v Marek Gengel | 1-6,4-6 |
| ITF M15 Jerusalem | 2021/05/14 07:30 | Zane Khan v Marek Gengel | 7-5,7-6 |
| ITF M15 Jerusalem | 2021/05/13 10:35 | Alexandros Skorilas v Marek Gengel | 2-6,1-6 |