| ITF Spain F13 | 2014/06/14 14:55 | Frederik Nielsen v David Perez Sanz | 6-4,6-1 |
| UTR Pro Tennis Series Barcelona | 2021/06/22 11:00 | Kuzey Cekirge v David Perez Sanz | 6-1,6-6 |
| UTR Pro Tennis Series Barcelona | 2021/06/21 14:00 | Ihor Dudun v David Perez Sanz | 1-6,6-3,6-4 |
| UTR Pro Tennis Series Barcelona | 2021/02/04 12:30 | Franco Feitt v David Perez Sanz | 3-3 |
| UTR Pro Tennis Series Barcelona | 2021/02/01 10:30 | Johan Sebastien Tatlot v David Perez Sanz | 3-6,6-4,5-4 |
| ITF M15 Monastir | 2021/01/10 14:00 | David Perez Sanz v Joshua D Karpenschif | 2-6,7-5,6-10 |
| ITF M15 Monastir | 2021/01/06 08:00 | David Perez Sanz v Ronan Joncour | 6-2,6-7,3-6 |
| ITF M15 Parnu | 2020/11/04 13:05 | David Perez Sanz v Simon Freund | 6-7,3-6 |
| ITF M15 Parnu | 2020/11/02 08:00 | David Perez Sanz v Kristofer Siimar | 6-3,6-3 |
| ATP Doha | 2021/03/06 09:00 | Frederik Nielsen v Ramkumar Ramanathan | 4-6,1-6 |
| Tennis Point Exhibition Series | 2020/07/18 11:35 | Sebastian Mortier v Frederik Nielsen | 4-6,3-6 |
| Tennis Point Exhibition Series | 2020/07/17 09:25 | Sebastian Fanselow v Frederik Nielsen | 6-3,6-7,2-6 |
| Tennis Point Exhibition Series | 2020/07/16 11:45 | Dominik Fritsche v Frederik Nielsen | 1-6,2-6 |
| Tennis Point Exhibition Series | 2020/07/15 14:05 | Julien Penzlin v Frederik Nielsen | 2-6,1-6 |
| Tennis Point Exhibition Series | 2020/07/14 09:50 | Julian Worn v Frederik Nielsen | 3-6,1-6 |
| Davis Cup | 2020/03/07 12:40 | Frederik Nielsen v Ignacio Garcia | 7-6,6-2 |
| ATP New York | 2020/02/09 20:30 | Go Soeda v Frederik Nielsen | 6-1,6-2 |