Stadium: Court 2 Round: 62 Ground: Hardcourt outdoor
| ITF M15 Ithaca | 2021/11/04 13:55 | Felix Corwin v Alex Knaff | 5-7,7-6,7-5 |
| ITF M15 Ithaca | 2021/11/03 15:30 | Radu Mihai Papoe v Alex Knaff | 6-4,3-6,0-6 |
| ITF M15 Tallahassee | 2021/10/27 13:55 | Alex Knaff v Sho Shimabukuro | 4-6,6-4,4-6 |
| ITF M15 Tallahassee | 2021/10/26 13:00 | Blu Baker v Alex Knaff | 6-7,5-7 |
| ITF M15 Tallahassee | 2021/10/25 13:00 | Alex Knaff v Matthew Dellavedova | 6-4,6-2 |
| ITF M25 Setubal | 2021/10/05 10:00 | Arthur Cazaux v Alex Knaff | 6-1,6-7,10-5 |
| ITF M25 Setubal | 2021/10/04 10:00 | Aditya Katticaren v Alex Knaff | 0-6,0-6 |
| ITF M15 Forbach | 2021/09/27 13:30 | Millen Hurrion v Alex Knaff | 6-3,6-7,10-3 |
| ITF M15 Oldenzaal | 2021/08/16 10:30 | George Loffhagen v Jarno Jans | 6-2,7-5 |
| ITF M15 Oldenzaal | 2021/08/15 07:30 | Jarno Jans v Paulo A S Dos Santos | 7-5,6-1 |
| ITF M25 The Hague | 2021/06/27 08:00 | Mick Veldheer v Jarno Jans | 6-4,6-1 |