Stadium: Court 7 Round: 62 Ground: Clay
| ITF M15 Novi Sad | 2021/08/02 12:30 | Alen Rogic-Hadzalic v Alex Knaff | 2-6,1-6 |
| ITF M15 Novi Sad | 2021/08/01 14:00 | Alex Knaff v Admir Kalender | 7-5,6-4 |
| ITF M15 Novi Sad | 2021/07/27 09:05 | Alex Knaff v Bekkhan Atlangeriev | 4-6,2-6 |
| ITF M15 Novi Sad | 2021/07/26 12:00 | Alex Knaff v Tomislav Jotovski | 5-7,6-2,11-9 |
| ITF M15 Novi Sad | 2021/07/25 10:45 | Luka Pavlovic v Alex Knaff | 6-7,7-5,13-15 |
| ITF M15 Esch/Alzette | 2021/07/20 15:45 | Marlon Vankan v Alex Knaff | 6-4,6-4 |
| Davis Cup | 2021/06/18 10:30 | Valentin Vacherot v Alex Knaff | 6-2,6-3 |
| Davis Cup | 2021/06/16 09:50 | Alex Knaff v Simon Carr | 3-6,2-6 |
| ITF M15 Novi Sad | 2021/08/02 08:00 | Sabit Suntic v Roko Horvat | 1-6,1-6 |
| ITF M15 Novi Sad | 2021/07/26 07:30 | Tadeas Paroulek v Roko Horvat | 6-4,7-5 |
| ITF M15 Novi Sad | 2021/07/25 09:30 | Roko Horvat v Lazar Vojinovic | 6-2,3-6,10-3 |
| ITF M15 Doboj | 2021/07/11 13:45 | Roko Horvat v Nicolas Bruna | 6-1,2-6,8-10 |
| ITF M25 Velenje | 2021/07/05 16:20 | Peter Goldsteiner v Roko Horvat | 7-6,6-4 |
| ITF M25 Velenje | 2021/07/04 07:30 | Pietro Schiavetti v Roko Horvat | 6-2,3-6,6-10 |
| UTR Pro Tennis Series Zadar | 2021/07/03 07:00 | Matija Pecotic v Roko Horvat | 6-3,5-4 |
| UTR Pro Tennis Series Zadar | 2021/07/01 08:00 | Roko Horvat v Anatoliy Petrenko | 6-2,6-1 |