Stadium: Court 9 Round: 25 Ground: Clay
| UTR Pro Tennis Series Zadar | 2021/11/19 09:00 | Vladyslav Manafov v Duje Kekez | 6-3,2-6,6-3 |
| UTR Pro Tennis Series Zadar | 2021/11/18 12:00 | Valerii Naumenko v Duje Kekez | 0-6,0-6 |
| UTR Pro Tennis Series Zadar | 2021/11/16 12:00 | Robert Rumler v Duje Kekez | 2-6,4-6 |
| UTR Pro Tennis Series Zadar | 2021/11/14 12:00 | Vladimir Popov v Duje Kekez | 0-6,2-6 |
| UTR Pro Tennis Series Nis | 2021/10/09 10:15 | Alexander Lazov v Duje Kekez | 6-3,3-6,5-1 |
| UTR Pro Tennis Series Nis | 2021/10/08 17:00 | Duje Kekez v Lazar Radenkovic | 6-1,5-1 |
| UTR Pro Tennis Series Nis | 2021/10/07 14:00 | Duje Kekez v Vladimir Popov | 6-0,5-1 |
| UTR Pro Tennis Series Nis | 2021/10/06 10:00 | Ivan Denisov v Duje Kekez | 1-6,4-6 |
| ITF M25 Pardubice | 2021/09/20 10:00 | Matthias Uwe Kask v Dominik Recek | 0-6,0-6 |
| ITF M25 Pardubice | 2021/09/19 09:00 | Matthias Uwe Kask v Vojtech Mares | 6-4,4-6,10-3 |
| ITF M15 Parnu | 2021/08/02 08:00 | Martins Rocens v Matthias Uwe Kask | 6-4,6-1 |
| ITF M15 Sibenik | 2021/05/16 12:30 | Leon Benedict v Matthias Uwe Kask | 4-6,6-2,10-6 |
| ITF M15 Sibenik | 2021/04/19 13:50 | Matthias Uwe Kask v Luigi Castelletti | 5-7,6-2,15-17 |
| ITF M15 Opatija | 2021/03/21 11:00 | Matthias Uwe Kask v Bozo Barun | 2-6,4-6 |