Stadium: Court 4 Round: 25 Ground: Clay
| ITF Russia F6 | 2018/08/14 09:45 | Ratniuk, Maxim v Kalovelonis, Markos | 6-4,7-5 |
| ITF M15 Parnu | 2019/07/18 12:25 | Luigi Sorrentino v Ratniuk, Maxim | 6-2,7-6 |
| ITF M15 Vilnius | 2019/07/10 08:00 | Ratniuk, Maxim v Alexey Zakharov | 4-6,4-6 |
| ITF M15 Wroclaw | 2019/07/03 08:00 | Ratniuk, Maxim v Oleg Prihodko | 6-3,2-6,1-6 |
| ITF - M25 Kiseljak | 2019/05/28 11:40 | Jordan Correia Passos Do Carmo v Ratniuk, Maxim | 6-3,6-3 |
| ITF - M15 Brcko | 2019/05/23 08:30 | Ratniuk, Maxim v Christopher O'Connell | 1-6,1-6 |
| ITF - M15 Brcko | 2019/05/22 07:00 | Ratniuk, Maxim v Milenkovic, Nebojsa | 6-3,6-0 |
| Namangan, Singles Qualifying M-ITF-UZB-02A | 2019/05/01 10:00 | Ratniuk, Maxim v Minin, Matvey | 6-7,2-6 |
| ITF - M15 Antalya | 2019/04/17 14:15 | Ratniuk, Maxim v Niklas-Salminen, Patrick | 4-6,2-6 |
| Nonthaburi, Singles M-ITF-THA-01A | 2019/07/30 07:40 | Kalovelonis, Markos v Yu Hsiou Hsu | 3-6,2-6 |
| Nonthaburi, Singles M-ITF-THA-01A | 2019/07/24 02:00 | Kalovelonis, Markos v Boyer, Dusty H | 3-6,6-7 |
| ITF M15 Belgrade | 2019/07/03 14:45 | Spec, Matic v Kalovelonis, Markos | 6-4,7-5 |
| ITF M15 Akko | 2019/06/13 07:00 | Kalovelonis, Markos v Smilansky, Igor | 7-6,3-6,1-6 |
| ITF M15 Akko | 2019/06/12 08:00 | Kalovelonis, Markos v Boris Pokotilov | 7-6,6-4 |
| ITF - M15 Héraklion | 2019/06/01 09:10 | Kalovelonis, Markos v Pervolarakis, Michail | 4-6,0-6 |
| ITF - M15 Héraklion | 2019/05/31 07:00 | Kobelt, Peter v Kalovelonis, Markos | 4-6,4-6 |
| ITF - M15 Héraklion | 2019/05/30 09:50 | Paris, Joshua v Kalovelonis, Markos | 4-6,6-3,3-6 |