Stadium: Court 1 Round: 25
| Challenger Loughborough Qual | 2018/05/21 09:30 | Johannes Haerteis v Frederik Nielsen | 6-7,1-6 |
| Challenger Loughborough Qual | 2018/05/20 09:30 | Simon Carr v Frederik Nielsen | 3-6,4-6 |
| Challenger Loughborough Qual | 2018/05/19 09:00 | Remi Boutillier v Frederik Nielsen | 7-6,6-7,1-6 |
| Challenger Busan Qual | 2018/05/14 03:30 | Yosuke Watanuki v Frederik Nielsen | 1-6,6-4,6-0 |
| Challenger Busan Qual | 2018/05/13 04:10 | Frederik Nielsen v Wishaya Trongcharoenchaikul | 6-7,6-4,6-0 |
| Challenger Seoul Qual | 2018/04/28 04:30 | Yong-Kyu Lim v Frederik Nielsen | 6-4,6-1 |
| Cupa Davis | 2018/04/07 10:00 | Frederik Nielsen v Karim-Mohamed Maamoun | 6-3,3-6,6-7 |
| Challenger Drummondville Qual | 2018/03/12 22:55 | Frederik Nielsen v Aleksandar Vukic | 2-6,4-6 |
| ITF Tunisia F18 | 2018/05/13 09:00 | David Guez v Andres Artunedo Martinavarr | 6-1,6-1 |
| ITF Tunisia F18 | 2018/05/12 09:00 | David Guez v Moez Echargui | 6-1,7-5 |
| ITF Tunisia F18 | 2018/05/11 11:00 | David Guez v Diego Hidalgo | 6-4,6-2 |
| ITF Tunisia F18 | 2018/05/10 09:00 | David Guez v Vasko Mladenov | 6-1,6-4 |
| ITF Tunisia F18 | 2018/05/09 11:05 | David Guez v Lawrence Bataljin | 6-3,6-2 |
| Challenger - Glasgow | 2018/05/05 10:00 | Lukas Lacko v David Guez | 6-3,6-4 |
| Challenger - Glasgow | 2018/05/04 11:05 | David Guez v Daniel Brands | 6-4,5-7,6-2 |
| Challenger - Glasgow | 2018/05/03 13:30 | David Guez v Robin Kern | 4-6,7-6,6-4 |