Stadium: Court 2 Round: 28 Ground: Hardcourt indoor
| Challenger St. Petersburg MD | 2021/03/11 13:05 | Kopriva V / Vrbensky M v De Jong/Verbeek | 0-6,3-6 |
| Challenger St. Petersburg MD | 2021/03/10 14:30 | Golubev/Tiurnev v De Jong/Verbeek | 4-6,6-7 |
| Challenger St. Petersburg MD | 2021/03/06 13:45 | De Jong/Verbeek v Eubanks/Quiroz | 4-6,3-6 |
| Challenger St. Petersburg MD | 2021/03/05 13:45 | De Jong/Verbeek v Bega/Mansouri | 6-2,6-3 |
| Challenger St. Petersburg MD | 2021/03/04 12:45 | De Jong/Verbeek v Kotov P / Safiullin R | 6-2,6-2 |
| Challenger St. Petersburg MD | 2021/03/03 11:00 | De Jong/Verbeek v Kirkin/Molleker | 6-2,3-6,10-6 |
| Challenger St. Petersburg MD | 2021/03/11 14:10 | Karlovskiy E / Serdarusic N v Pasha N / Schnur M | 6-7,6-3,10-4 |
| Challenger St. Petersburg MD | 2021/03/10 07:00 | Karlovskiy E / Serdarusic N v Sels J / van Rijthoven T | 6-1,6-2 |
| Challenger St. Petersburg MD | 2021/03/03 14:20 | Gabashvili T / Kravchuk K v Karlovskiy E / Serdarusic N | 6-3,6-4 |
| Challenger Charlottesville MD | 2018/11/01 21:45 | Paes L / Reyes-Varela M v Karlovskiy E / Serdarusic N | 4-6,7-6,13-11 |
| Challenger Charlottesville MD | 2018/10/29 16:55 | Karlovskiy E / Serdarusic N v Lord M / Ross G | 4-6,6-1,10-3 |
| Challenger Charlottesville MD | 2018/10/28 20:20 | Karlovskiy E / Serdarusic N v Choinski J / Majchrzak K | 7-6,6-2 |