Stadium: Court 01 Round: 25 Ground: Clay
| ITF Italy F15 | 2018/06/23 12:00 | Andrea Guerrieri v Peter Heller | 1-6,3-6 |
| ITF M25 Wetzlar | 2021/08/08 10:00 | Peter Heller v Christopher Heyman | 6-4,6-7,6-4 |
| ITF M25 Wetzlar | 2021/08/07 11:00 | David Pichler v Peter Heller | 3-6,7-5,3-6 |
| ITF M25 Wetzlar | 2021/08/06 15:55 | Constantin Schmitz v Peter Heller | 3-6,7-5,1-6 |
| ITF M25 Wetzlar | 2021/08/05 09:00 | Georgii Kravchenko v Peter Heller | 6-7,2-6 |
| ITF M25 Wetzlar | 2021/08/04 08:00 | Marvin Moeller v Peter Heller | 2-6,3-6 |
| Challenger Salzburg | 2021/07/08 10:30 | Nicolas Jarry v Peter Heller | 6-2,6-4 |
| Challenger Salzburg | 2021/07/05 10:35 | Francisco Cerundolo v Peter Heller | 3-6,6-3,3-6 |
| ITF M15 - Antalya | 2021/05/06 08:10 | Nick Hardt v Peter Heller | 3-6,6-0,7-5 |
| ITF M15 Gdyně | 2021/08/09 08:00 | Andrea Guerrieri v Juliusz Bienkiewicz | 6-2,2-6,7-10 |
| ITF M15 Parnu | 2021/08/05 09:55 | Yan Sabanin v Andrea Guerrieri | 6-2,6-3 |
| ITF M15 Parnu | 2021/08/04 16:00 | Andrea Guerrieri v Johannes Seeman | 2-6,7-6,6-4 |
| ITF M15 Bergamo | 2021/06/21 12:00 | Andrea Guerrieri v Francesco Vilardo | 6-7,6-2,10-12 |
| ITF M15 Janov | 2021/06/15 08:50 | Juan Bautista Otegui v Andrea Guerrieri | 6-3,6-1 |
| ITF M15 Janov | 2021/06/14 07:00 | Giorgio Tabacco v Andrea Guerrieri | 6-3,3-6,6-10 |
| ITF M15 Gaiba | 2021/06/09 08:45 | Andrea Guerrieri v Giovanni Fonio | 7-5,3-6,3-6 |
| ITF M15 Gaiba | 2021/06/07 11:40 | Andrea Guerrieri v Gabriele Moghini | 7-6,6-4 |