Stadium: Court 5 Round: 44 Ground: Clay
| ITF M25 Jablonec Nad Nisou | 2021/05/17 08:30 | Andrew Paulson v Leon Hoeveler | 6-1,6-2 |
| ITF M25 Jablonec Nad Nisou | 2021/05/16 07:30 | Andrew Paulson v Vojtech Vlkovsky | 6-1,6-4 |
| ITF M25 Prague | 2021/05/12 09:10 | Dalibor Svrcina v Andrew Paulson | 7-6,6-1 |
| ITF M25 Prague | 2021/05/11 08:00 | Filip Peliwo v Andrew Paulson | 1-6,4-6 |
| ITF M25 Prague | 2021/05/10 08:00 | Victor Sklenka v Andrew Paulson | 1-6,2-6 |
| ITF M25 Prague | 2021/05/09 07:30 | Jakub Katuch v Andrew Paulson | 3-6,6-3,6-10 |
| Challenger Prague | 2021/05/04 09:55 | Andrew Paulson v Andrej Martin | 3-6,3-6 |
| Challenger Ostrava | 2021/04/25 10:00 | Andrew Paulson v Lukas Klein | 6-2,3-6,2-6 |
| ITF M25 Jablonec Nad Nisou | 2021/05/17 07:30 | Jan Jermar v Kai Lemstra | 4-6,4-6 |
| ITF M25 Jablonec Nad Nisou | 2021/05/16 08:30 | Matyas Cerny v Kai Lemstra | 3-6,3-6 |
| ITF M25 Meerbusch | 2021/04/12 09:30 | Marvin Netuschil v Kai Lemstra | 6-2,6-3 |
| ITF M15 Monastir | 2021/03/15 12:30 | Kai Lemstra v Alexander Kotzen | 1-6,3-6 |
| ITF M15 Monastir | 2021/03/15 08:00 | Kai Lemstra v John Sperle | 6-3,6-3 |
| ITF M15 Monastir | 2021/03/14 08:00 | Guy Orly Iradukunda v Kai Lemstra | 3-6,5-7 |
| ITF M15 Monastir | 2021/03/11 10:40 | Kai Lemstra v Juan Bautista Torres | 4-6,1-6 |
| ITF M15 Monastir | 2021/03/10 12:15 | Kai Lemstra v Christoph Negritu | 6-4,2-6,6-1 |