| Challenger - Maia | 11/29 13:10 | 19 | [374] Duje Ajdukovic v Nikolas S Izquierdo [356] | 3-6,7-6,7-5 | |
| Challenger - Maia | 11/28 15:40 | 64 | [114] Harri Heliovaara v Nikolas S Izquierdo [356] | 2-6,4-6 | |
| ITF M15 - Villena | 11/21 08:50 | 28 | [251] Marco Trungelliti v Nikolas S Izquierdo [359] | 6-1,6-1 | |
| ITF M15 - Villena | 11/20 09:00 | 27 | [359] Nikolas S Izquierdo v Mathieu Perchicot [456] | 6-4,7-5 | |
| ITF M15 - Villena | 11/19 11:10 | 26 | [359] Nikolas S Izquierdo v Ivan Gakhov [352] | 6-3,7-6 | |
| ITF M15 - Villena | 11/18 12:05 | 25 | Nikolas S Izquierdo v Nicolas Moreno De Alboran | 6-2,7-6 | |
| ITF M15 - Valldoreix | 11/14 09:50 | 28 | [358] Nikolas S Izquierdo v Javier Barranco Cosano [314] | 6-4,0-6,3-6 | |
| ITF M15 - Valldoreix | 11/13 08:55 | 27 | [371] Pedro Cachin v Nikolas S Izquierdo [358] | 4-6,3-6 | |
| ITF M15 - Valldoreix | 11/12 08:55 | 26 | Nicolas Moreno De Alboran v Nikolas S Izquierdo | 4-6,2-6 | |
| ITF M15 - Valldoreix | 11/10 14:55 | 25 | Pedro Vives Marcos v Nikolas S Izquierdo | 2-6,2-6 | |
| ITF M25 Vale Do Lobo | 10/29 12:25 | 26 | [375] Pedro Cachin v Nikolas S Izquierdo [356] | Retired | |
| ITF M25 Vale Do Lobo | 10/28 11:45 | 25 | Nikolas S Izquierdo v Joao Lucas Reis da Silva | 3-6,7-5,6-4 | |
| ITF M25 - Hamborg | 10/20 09:55 | 25 | [356] Nikolas S Izquierdo v Tim Van Rijthoven [345] | 6-2,5-7,4-6 | |
| ITF M25 Rodez | 10/14 07:55 | 25 | [383] Sadio Doumbia v Nikolas S Izquierdo [356] | 7-6,6-3 | |
| Challenger - Barcelona | 10/04 10:20 | 164 | [201] Brandon Nakashima v Nikolas S Izquierdo [352] | 6-1,6-2 | |
| Challenger - Barcelona | 10/03 13:45 | 26 | [352] Nikolas S Izquierdo v Mathias Bourgue [211] | 6-3,6-0 | |
| ITF M25 - Pardubice | 09/30 13:00 | 25 | Juan Manuel Cerundolo v Nikolas S Izquierdo | 5-7,6-1,10-3 | |
| ITF M25 - Pardubice | 09/30 12:30 | 25 | [342] Juan Manuel Cerundolo v Nikolas S Izquierdo [352] | 5-7,6-1,0-0 | |
| Challenger - Forli | 09/22 14:00 | 25 | [87] Salvatore Caruso v Nikolas S Izquierdo [355] | 7-6,7-6 | |
| Challenger - Forli | 09/20 08:30 | 164 | [318] Alexander Ritschard v Nikolas S Izquierdo [355] | 1-6,2-6 | |
| Challenger - Forli | 09/19 09:40 | 64 | [395] Ronald Slobodchikov v Nikolas S Izquierdo [355] | Retired | |
| ITF M25 - Prag | 09/16 08:00 | 25 | [379] Pedro Cachin v Nikolas S Izquierdo [355] | 6-1,6-4 | |
| ITF M15 - Anif | 08/29 08:00 | 28 | [407] Peter Heller v Nikolas S Izquierdo [357] | 6-1,6-1 | |
| ITF M15 - Anif | 08/28 07:55 | 27 | [415] Matias Franco Descotte v Nikolas S Izquierdo [357] | 2-6,3-6 | |
| ITF M15 - Anif | 08/27 08:00 | 26 | [445] Francesco Forti v Nikolas S Izquierdo [357] | 4-6,6-3,5-7 | |
| ITF M15 - Anif | 08/26 13:05 | 25 | Duje Ajdukovic v Nikolas S Izquierdo | 6-7,1-6 | |
| Challenger - Todi | 08/15 10:45 | 64 | [279] Borna Gojo v Nikolas S Izquierdo [356] | 6-4,6-0 | |
| Spanien - Summer League | 07/31 15:30 | - | [356] Nikolas S Izquierdo v Steven Diez [165] | 6-7,6-4,2-6 | |
| Spanien - Summer League | 07/30 15:00 | - | Nikolas S Izquierdo v Sergi Perez Contri | 6-2,6-1 | |
| Spanien - Summer League | 07/24 08:00 | - | [356] Nikolas S Izquierdo v Carlos Taberner [175] | 4-6,6-3,1-6 |