Stadium: Court 4 Round: 24 Ground: Clay
| ATP Belgrade MD | 2021/05/23 15:20 | Sabanov/Sabanov v Brkic/Cacic | 4-6,6-3,10-8 |
| ATP Geneva MD | 2021/05/20 12:15 | Brkic/Cacic v Bolelli/Gonzalez | 3-6,6-7 |
| ATP Geneva MD | 2021/05/19 10:30 | Marach/Pavic v Brkic/Cacic | 6-7,2-6 |
| ATP Munich MD | 2021/04/28 10:20 | Brkic/Cacic v Ebden/Smith | 6-7,6-7 |
| ATP Belgrade MD | 2021/04/23 11:00 | Behar/Escobar v Brkic/Cacic | 6-3,6-4 |
| ATP Belgrade MD | 2021/04/22 10:00 | Brkic/Cacic v Bolelli/Gonzalez | 0-6,7-6,10-8 |
| ATP Belgrade MD | 2021/04/21 11:00 | Arevalo/Middelkoop v Brkic/Cacic | 4-6,6-7 |
| Challenger Belgrade MD | 2021/04/17 12:10 | Duran/Molteni v Brkic/Cacic | 6-4,6-4 |