Stadium: Court 3 Round: 44 Ground: Clay
| ITF M15 Antalya | 2021/10/19 09:20 | Dan Alexandru Tomescu v Gian Marco Ortenzi | 5-7,7-6,11-9 |
| ITF M15 Antalya | 2021/10/18 12:00 | Vitek Horak v Gian Marco Ortenzi | 6-4,3-6,7-10 |
| ITF M15 Antalya | 2021/10/17 07:00 | Aziz Dadabaev v Gian Marco Ortenzi | 2-6,3-6 |
| ITF M15 Antalya | 2021/10/12 11:05 | Gian Marco Ortenzi v Facundo Yunis | 5-7,6-7 |
| ITF M15 Antalya | 2021/10/11 09:00 | Gian Marco Ortenzi v Simon Habsuda | 6-4,6-0 |
| ITF M15 Cairo | 2021/09/30 10:20 | Simone Roncalli v Gian Marco Ortenzi | 2-6,6-3,6-0 |
| ITF M15 Cairo | 2021/09/29 14:50 | Gian Marco Ortenzi v Elbert Barr | 6-0,6-2 |
| ITF M15 Cairo | 2021/09/28 10:20 | Gian Marco Ortenzi v Daiki Yoshimura | 6-2,4-6,10-4 |
| ITF M15 Platja D'Aro | 2021/10/10 10:00 | Stefan Cizelj-Zivkovic v Noah Lopez | 1-6,3-6 |
| ITF M15 Platja D'Aro | 2021/10/05 08:00 | Stefan Cizelj-Zivkovic v Jorge Martinez Martinez | 0-6,1-6 |
| ITF M15 Platja D'Aro | 2021/10/03 08:00 | Zhenxiong Dong v Stefan Cizelj-Zivkovic | 4-6,4-6 |
| ITF M15 Cairo | 2021/09/12 08:00 | Andrei Cuceu v Stefan Cizelj-Zivkovic | 6-4,6-3 |
| ITF M15 Cairo | 2021/09/05 08:30 | Lucio Carnevalle v Stefan Cizelj-Zivkovic | 6-3,6-2 |
| ITF M25 Velenje | 2021/07/05 12:15 | Stefan Cizelj-Zivkovic v Lukas Palovic | 3-6,1-6 |
| ITF M25 Velenje | 2021/07/04 07:30 | Stefan Cizelj-Zivkovic v Marco Mania | 7-6,6-0 |
| ITF M15 Tbilisi | 2021/05/17 05:30 | Aleksandr Braynin v Stefan Cizelj-Zivkovic | 6-4,6-3 |