Stadium: Kvarner 3 Round: 60 Ground: Clay
| ITF Croatia F2 | 2018/03/14 09:00 | Kai Lemstra v Bruno Santanna | 3-6,3-6 |
| ITF Croatia F2 | 2018/03/13 08:00 | Kai Lemstra v Valentin Royer | 1-6,6-4,6-3 |
| ITF Croatia F2 | 2018/03/11 08:00 | Kai Lemstra v Marco De Rosa | 6-2,6-3 |
| ITF Croatia F1 | 2018/03/07 09:00 | Anze Arh v Kai Lemstra | 7-5,6-1 |
| ITF Germany F3 Qual | 2018/01/29 16:30 | Dominik Boehler v Kai Lemstra | 7-6,7-6 |
| ITF Germany F3 Qual | 2018/01/28 17:00 | Charley Emhardt v Kai Lemstra | 1-6,2-6 |
| ITF Germany F2 | 2018/01/23 15:35 | Kai Lemstra v Pedro Cachin | 3-6,3-6 |
| ITF Germany F1 | 2018/01/11 17:10 | Elmar Ejupovic v Kai Lemstra | 6-3,6-4 |
| ITF Croatia F3 | 2018/03/18 10:30 | Michelangelo Endrizzi v Giovanni Agostinetto | 0-6,7-5,6-3 |
| ITF Croatia F2 | 2018/03/11 08:00 | Michelangelo Endrizzi v Valentin Royer | 5-7,2-6 |
| ITF Turkey F48 Qual | 2017/12/17 07:45 | Luca George Tatomir v Michelangelo Endrizzi | 6-3,6-2 |
| ITF Turkey F47 Qual | 2017/12/11 08:45 | Diego Hidalgo v Michelangelo Endrizzi | 6-3,6-0 |
| ITF Turkey F47 Qual | 2017/12/10 07:15 | Michelangelo Endrizzi v Alexandru Vasile Manole | 6-4,6-4 |
| ITF Turkey F46 Qual | 2017/12/04 07:15 | Jakob Johansson-Holm v Michelangelo Endrizzi | 6-2,6-0 |
| ITF Turkey F46 Qual | 2017/12/03 07:15 | Michelangelo Endrizzi v Patryk Krolik | 6-4,6-2 |
| ITF Italy F25 Qual | 2017/08/05 08:30 | Michelangelo Endrizzi v Thomas Colautti | 4-6,2-6 |