Stadium: Centre Court Round: 25 Ground: Clay
| ITF M25 Montauban | 2021/06/24 10:00 | Valentin Royer v Dayne Kelly | 7-6,6-2 |
| ITF M25 Montauban | 2021/06/23 08:25 | Loris Pourroy v Dayne Kelly | 4-6,4-6 |
| Challenger Orlando | 2021/06/08 16:00 | Dayne Kelly v Guido Andreozzi | 6-4,4-6,5-7 |
| Challenger Orlando | 2021/06/07 16:00 | Sekou Bangoura v Dayne Kelly | 6-7,3-6 |
| Challenger Orlando | 2021/06/06 19:00 | Dayne Kelly v Michael Redlicki | 6-2,6-1 |
| Challenger Little Rock | 2021/06/03 17:00 | Dayne Kelly v Oliver Crawford | 4-6,1-6 |
| Challenger Little Rock | 2021/06/02 16:30 | Dayne Kelly v Nick Chappell | 6-1,7-5 |
| Challenger Little Rock | 2021/05/31 15:00 | Gage Brymer v Dayne Kelly | 2-6,1-6 |
| ITF M25 The Hague | 2021/06/28 09:40 | Guy Den Heijer v Max Van Nunen | 6-3,6-1 |
| ITF M25 The Hague | 2021/06/27 08:00 | Guy Den Heijer v Jing L Weng | 6-3,6-4 |
| ITF M25 Alkmaar | 2021/06/23 09:00 | Kaichi Uchida v Guy Den Heijer | 7-6,6-3 |
| ITF M25 Alkmaar | 2021/06/21 18:00 | Vladimir Ivanov v Guy Den Heijer | 3-6,6-7 |
| ITF M25 Alkmaar | 2021/06/20 17:00 | Alec Deckers v Guy Den Heijer | 3-6,7-6,4-10 |
| ITF M25 Vic | 2021/05/16 08:00 | Mateus Alves v Guy Den Heijer | 6-2,6-3 |
| ITF M15 Valldoreix | 2021/05/09 13:00 | Guy Den Heijer v Pol Amoros Ramos | 3-6,2-6 |
| ITF M15 Majadahonda | 2021/05/02 16:15 | Taiyo Yamanaka v Guy Den Heijer | 6-7,6-3,11-9 |