Ground: Hardcourt indoor
| ITF M25 Glasgow | 2019/02/22 13:00 | Igor Sijsling v Jahn, Jeremy | 5-7,1-6 |
| Challenger Wroclaw | 2017/02/28 12:40 | Igor Sijsling v Jahn, Jeremy | 6-4,6-2 |
| ITF M25 Glasgow | 2019/02/22 13:00 | Igor Sijsling v Jahn, Jeremy | 5-7,1-6 |
| ITF M25 Glasgow | 2019/02/21 10:00 | Igor Sijsling v Fawcett, Tom | 6-2,6-1 |
| ITF M25 Glasgow | 2019/02/19 10:00 | Benjamin Hassan v Igor Sijsling | 5-7,3-6 |
| Barnstaple, Singles Qualifying M-ITF-GBR-01A | 2019/02/12 11:25 | Igor Sijsling v Hoyt, Evan | 6-7,4-6 |
| ITF M15 Kaarst | 2019/02/10 12:00 | Igor Sijsling v Botic Van De Zandschulp | 6-1,6-4 |
| ITF M15 Kaarst | 2019/02/09 14:05 | Igor Sijsling v Stanek, Robin | 6-3,6-0 |
| ITF M15 Kaarst | 2019/02/08 12:00 | Igor Sijsling v Lucas Gerch | 6-4,6-4 |
| ITF M15 Kaarst | 2019/02/07 13:10 | Igor Sijsling v Veldheer, Mick | 6-2,6-2 |
| ITF M25 Glasgow | 2019/02/22 13:00 | Igor Sijsling v Jahn, Jeremy | 5-7,1-6 |
| ITF M25 Glasgow | 2019/02/21 10:00 | Felix Corwin v Jahn, Jeremy | 6-2,6-7,4-6 |
| ITF M25 Glasgow | 2019/02/19 10:00 | Aidan Mchugh v Jahn, Jeremy | 3-6,6-2,4-6 |
| ITF M15 Palmanova | 2019/01/24 11:30 | Jahn, Jeremy v Carlos Lopez Montagud | 6-7,1-6 |
| ITF M15 Palmanova | 2019/01/22 11:05 | Jahn, Jeremy v Salman, Omar | 6-2,6-4 |
| Challenger Da Nang | 2019/01/06 06:50 | Benjamin Hassan v Jahn, Jeremy | 6-2,1-6,6-3 |
| Hong Kong, Simples M-ITF-HKG-04A | 2019/01/03 02:00 | Shintaro Imai v Jahn, Jeremy | 6-4,6-4 |
| Hong Kong, Simples M-ITF-HKG-04A | 2019/01/02 05:00 | Gao, Xin v Jahn, Jeremy | 0-6,3-6 |