Stadium: Court 9 Round: 54 Ground: Clay
| ITF M15 Champaign | 2021/06/21 15:00 | Seelig, Kyle v Harper, Cleeve | 6-2,6-1 |
| UTR Pro Tennis Series Florida | 2021/06/11 16:00 | Harper, Cleeve v Yatsuk, Ivan | 7-5,6-7,4-6 |
| UTR Pro Tennis Series Florida | 2021/06/09 14:30 | Harper, Cleeve v Andres Martin | 3-6,6-3,2-6 |
| UTR Pro Tennis Series Florida | 2021/06/08 14:30 | Harper, Cleeve v Thomas Brown | 6-3,5-1 |
| UTR Pro Tennis Series Florida | 2021/06/07 13:00 | Cooper Williams v Harper, Cleeve | 2-6,4-5 |
| UTR Pro Tennis Series Florida | 2020/08/14 13:25 | Mercier, Tyler v Harper, Cleeve | 4-6,0-6 |
| UTR Pro Tennis Series Florida | 2020/08/13 12:00 | Grigoriy Lomakin v Harper, Cleeve | 0-6,3-6 |
| UTR Pro Tennis Series Florida | 2020/08/12 13:40 | Thirouin, Jean v Harper, Cleeve | 6-2,4-6,8-10 |
| Houston, Singles Qualifying M-ITF-USA-28A | 2019/09/21 01:00 | Greif, Lukas v Rapp, Austin | 3-6,3-6 |
| Houston, Singles Qualifying M-ITF-USA-28A | 2019/09/20 00:00 | Harrison Adams v Greif, Lukas | 3-6,3-6 |
| Houston, Singles Qualifying M-ITF-USA-28A | 2019/09/19 00:00 | Greif, Lukas v Graziani, Edoardo | 6-4,7-5 |
| Houston, Singles Qualifying M-ITF-USA-28A | 2019/09/16 14:00 | Irizarry, Eduardo Neftali v Greif, Lukas | 3-6,2-6 |
| Houston, Singles Qualifying M-ITF-USA-28A | 2019/09/15 14:00 | Greif, Lukas v Abraham Asaba | 5-7,6-4,10-3 |
| ITF USA F12 | 2018/04/21 14:30 | Greif, Lukas v Alex Hernandez | 1-6,3-6 |
| ITF USA F12 | 2018/04/20 18:00 | Greif, Lukas v Mcmann, Conner | 6-3,6-0 |
| ITF USA F11 | 2018/04/16 14:00 | Greif, Lukas v Rowland Phillips | 5-7,6-7 |