| Sofia, Bulgaria | 11/04 18:45 | 14 | [173] Marc-Andrea Huesler v Erler, Alexander [41] | 6-1,7-5 | |
| ATP Vienna | 10/21 11:20 | 14 | [61] Emil Ruusuvuori v Erler, Alexander [34] | 6-1,7-5 | |
| Challenger Cagliari | 05/02 08:30 | 19 | [246] Alessandro Giannessi v Erler, Alexander [36] | 7-5,6-1 | |
| Challenger Cagliari | 05/01 09:40 | 14 | [60] Nedovyesov, Aleksandr v Erler, Alexander [36] | 3-6,6-3,5-7 | |
| Helsinki, Finland | 11/14 11:00 | 19 | [239] Mikhail Kukushkin v Erler, Alexander [49] | 6-2,7-6 | |
| Helsinki, Finland | 11/13 09:00 | 14 | [47] Erler, Alexander v Gauthier Onclin [331] | 7-6,7-6 | |
| ATP Vienna | 10/22 10:20 | 14 | [76] Erler, Alexander v Joao Sousa [67] | 6-7,5-7 | |
| Antwerp, Belgium | 10/17 10:00 | 19 | [113] van Rijthoven, Tim v Erler, Alexander [76] | 7-6,6-3 | |
| Antwerp, Belgium | 10/16 10:00 | 14 | [78] Erler, Alexander v Evan Furness [202] | 6-1,6-4 | |
| Challenger Sibiu | 09/19 11:00 | 19 | [376] Rudolf Molleker v Erler, Alexander [71] | 6-1,6-1 | |
| Challenger Sibiu | 09/18 14:05 | 14 | [72] Erler, Alexander v Marko Topo [471] | 7-5,6-3 | |
| Challenger Tulln | 09/04 13:35 | 14 | [229] Horansky, Filip v Erler, Alexander [83] | 3-6,6-3,6-2 | |
| Grodzisk Mazowiecki, Poland | 08/14 11:10 | 14 | [403] Beibit Zhukayev v Erler, Alexander [87] | 6-7,6-3,6-3 | |
| Challenger Liberec | 07/31 09:20 | 14 | Denis Yevseyev v Erler, Alexander | Cancelled | |
| Iasi, Romania | 07/10 15:00 | 14 | Ilya Snitari v Erler, Alexander | 6-3,6-3 | |
| Challenger Salzburg | 07/03 13:00 | 14 | Erler, Alexander v Filip C Jianu | Cancelled | |
| Prostejov, Czech Republic | 05/31 12:45 | 25 | [467] Erler, Alexander v Lukas Klein [327] | 4-6,0-6 | |
| Prostejov, Czech Republic | 05/30 08:00 | 19 | Giovanni M Perricard v Erler, Alexander | 5-7,2-6 | |
| Prostejov, Czech Republic | 05/29 08:00 | 14 | [467] Erler, Alexander v Juncheng Shang [401] | 4-6,7-6,6-4 | |
| Tunis, Tunisia | 05/18 11:30 | 26 | [319] Oriol Roca Batalla v Erler, Alexander [479] | 7-5,7-6 | |
| Tunis, Tunisia | 05/17 09:00 | 25 | [479] Erler, Alexander v Kimmer Coppejans [278] | 7-6,7-6 | |
| Tunis, Tunisia | 05/16 12:45 | 19 | [357] Menendez-Maceiras, Adrian v Erler, Alexander [479] | 1-6,7-6,6-7 | |
| Tunis, Tunisia | 05/15 13:45 | 14 | Youssef Labbene v Erler, Alexander | 7-6,2-6,6-7 | |
| ITF M15 Cairo | 05/11 08:00 | 25 | Erler, Alexander v Max Alcala Gurri | 4-6,1-6 | |
| Mauthausen, Austria | 05/01 13:35 | 14 | [301] Lukas Klein v Erler, Alexander [446] | 4-6,6-0,6-3 | |
| Challenger - Ostrava | 04/25 11:00 | 19 | [249] Lukas Rosol v Erler, Alexander [446] | 6-2,6-0 | |
| Challenger - Ostrava | 04/24 10:55 | 14 | Ondrej Horak v Erler, Alexander | 7-6,2-6,3-6 | |
| Challenger Prague | 04/17 08:30 | 14 | [403] Sebastian Fanselow v Erler, Alexander [395] | 6-1,7-5 | |
| Challenger Biel | 03/20 13:55 | 14 | [315] Paulson, Andrew v Erler, Alexander [371] | 7-5,6-3 | |
| Bengaluru 2, India, Qualifying | 02/13 08:40 | 14 | Dominik Palan v Erler, Alexander | 7-6,4-6,6-3 |