Stadium: Hard Court 6 Round: 54 Ground: Hardcourt outdoor
| ITF - M15 Héraklion | 2019/05/27 07:00 | Calum Puttergill v Keisidis, Christos | 4-6,3-6 |
| ITF - M15 Héraklion | 2019/05/20 07:00 | Keisidis, Christos v Thiem, Moritz | 2-6,3-6 |
| ITF M15 Sozopol | 2019/05/07 09:00 | Boris Pokotilov v Keisidis, Christos | 6-3,3-6,10-3 |
| ITF Bulgaria F1 | 2018/05/15 07:00 | Keisidis, Christos v Igoshin, Alexander | 4-6,6-1,1-6 |
| ITF Bulgaria F1 | 2018/05/13 07:00 | Palazov, Zlatan v Keisidis, Christos | 5-7,0-6 |
| ITF Serbia F8 Qual | 2016/09/17 07:00 | Hiramatsu, Shinnosuke v Keisidis, Christos | 6-4,6-3 |
| ITF Serbia F7 Qual | 2016/09/11 10:00 | Gojo, Borna v Keisidis, Christos | 6-2,6-2 |
| ITF Serbia F7 Qual | 2016/09/10 13:30 | Keisidis, Christos v Vladusic, Nenad | 6-4,6-2 |
| ITF - M15 Héraklion | 2019/05/27 07:00 | Yeshaya, Omer v Gian Marco Ortenzi | 2-6,4-6 |
| ITF M15 Las Palmas | 2019/05/08 08:00 | Carlos Sanchez Jover v Gian Marco Ortenzi | 6-4,6-1 |
| ITF M15 Las Palmas | 2019/05/07 08:30 | Gian Marco Ortenzi v Traviesa Mola, Oscar | 6-1,6-7,10-4 |
| ITF M15 Las Palmas | 2019/05/06 08:30 | Gian Marco Ortenzi v Hans Albert Schubert | 6-3,7-5 |
| ITF - M15 Sharm El Sheikh | 2019/04/10 09:55 | Gian Marco Ortenzi v Andrzejczuk, Adrian | 5-7,0-6 |
| ITF - M15 Sharm El Sheikh | 2019/04/09 09:10 | Cheruku, Vasisht v Gian Marco Ortenzi | 3-6,6-3,6-10 |
| ITF - M15 Sharm El Sheikh | 2019/04/08 08:00 | Solomatin, Igor v Gian Marco Ortenzi | 2-6,4-6 |
| Tunisia F40, Singles | 2018/11/11 08:00 | Gian Marco Ortenzi v Stable, Rayane | 4-6,1-6 |