Stadium: Court 4 Round: 27 Ground: Clay
| ATP Madrid MD | 2021/05/05 14:10 | Koolhof/Kubot v Demoliner/Medvedev | 7-5,6-7,10-3 |
| ATP Madrid MD | 2021/05/04 14:55 | Koolhof/Kubot v Tsitsipas/Tsitsipas | 6-4,5-7,10-6 |
| ATP Barcelona MD | 2021/04/19 10:00 | Koolhof/Kubot v Alcaraz/Carreno-Busta | 4-6,1-6 |
| ATP Monte Carlo MD | 2021/04/14 13:30 | Fognini/Schwartzman v Koolhof/Kubot | 1-6,6-4,10-7 |
| ATP Monte Carlo MD | 2021/04/13 12:55 | Mannarino/Paire v Koolhof/Kubot | 6-7,3-6 |
| ATP Miami MD | 2021/03/25 17:55 | Khachanov/Rublev v Koolhof/Kubot | 6-4,6-2 |
| ATP Dubai MD | 2021/03/17 11:10 | Koolhof/Kubot v Krawietz/Struff | 7-5,3-6,3-10 |
| ATP Dubai MD | 2021/03/15 09:00 | Koolhof/Kubot v Melo/Rojer | 6-4,0-6,12-10 |
| ATP Madrid MD | 2021/05/06 09:00 | Purcell/Saville v Mektic/Pavic | 6-4,3-6,4-10 |
| ATP Monte Carlo MD | 2021/04/18 10:00 | Evans/Skupski v Mektic/Pavic | 3-6,6-4,7-10 |
| ATP Monte Carlo MD | 2021/04/17 09:30 | Granollers/Zeballos v Mektic/Pavic | 6-3,5-7,4-10 |
| ATP Monte Carlo MD | 2021/04/16 10:15 | Herbert/Mahut v Mektic/Pavic | 3-6,1-6 |
| ATP Monte Carlo MD | 2021/04/15 11:20 | Behar/Escobar v Mektic/Pavic | 4-6,6-1,3-10 |
| ATP Miami MD | 2021/04/03 19:30 | Evans/Skupski v Mektic/Pavic | 4-6,4-6 |
| ATP Miami MD | 2021/04/01 17:00 | Ram/Salisbury v Mektic/Pavic | 3-6,6-7 |
| ATP Miami MD | 2021/03/31 17:00 | Kecmanovic/Qureshi v Mektic/Pavic | 2-6,2-6 |