| Exo Tennis Germany Series | 2020/07/14 13:50 | Penzlin, Julien v Hazem Naw | 1-6,2-6 |
| Exo Tennis Germany Series | 2020/07/14 09:50 | Worn, Julian v Nielsen, Frederik | 3-6,1-6 |
| Coupe Davis | 2020/03/07 12:40 | Nielsen, Frederik v Garcia, Ignacio | 7-6,6-2 |
| New York, USA | 2020/02/09 20:30 | Soeda, Go v Nielsen, Frederik | 6-1,6-2 |
| Challenger - Phoenix | 2019/03/13 18:40 | Nielsen, Frederik v Polansky, Peter | 6-7,3-6 |
| Challenger - Phoenix | 2019/03/11 17:00 | Nielsen, Frederik v Martin, Fabrice | 6-4,7-6 |
| Challenger Noumea | 2018/12/31 04:05 | Daniel Masur v Nielsen, Frederik | 6-1,5-7,6-4 |
| Challenger Fairfield | 2018/10/08 17:00 | King, Kevin v Nielsen, Frederik | 6-4,6-3 |
| Challenger Fairfield | 2018/10/07 18:15 | Thai-Son Kwiatkowski v Nielsen, Frederik | 7-6,3-6,5-7 |