| UTR Pro Tennis Series California | 2021/07/18 22:47 | Karl Lee v Nevin Arimilli | 5-7,6-7 |
| UTR Pro Tennis Series Nevada | 2021/07/03 16:30 | Bjorn Swenson v Karl Lee | 6-2,5-2 |
| UTR Pro Tennis Series Nevada | 2021/06/30 15:00 | Karl Lee v Aaron Bailey | 6-2,6-4 |
| UTR Pro Tennis Series Nevada | 2021/06/29 15:00 | Karl Lee v Bradley Frye | 3-6,6-7 |
| UTR Pro Tennis Series Nevada | 2021/06/28 18:00 | Karl Lee v Jared Pratt | 6-4,6-3 |
| UTR Pro Tennis Series California | 2021/02/14 16:00 | Kyle Kang v Karl Lee | 7-6,6-3 |
| UTR Pro Tennis Series California | 2021/02/13 20:30 | Alejandro Mendoza v Karl Lee | 3-6,4-5 |
| UTR Pro Tennis Series California | 2021/02/11 20:00 | Karl Lee v Isaiah Strode | 1-6,0-5 |
| UTR Pro Tennis Series California | 2021/07/19 18:00 | Aidan Kim v Julian Steinhausen | 6-3,6-4 |
| UTR Pro Tennis Series California | 2021/07/18 15:00 | Julian Steinhausen v Aaron Bailey | 3-6,6-2,6-2 |
| UTR Pro Tennis Series California | 2021/05/28 18:00 | Julian Steinhausen v Alexander Stater | 6-3,2-6,2-5 |
| UTR Pro Tennis Series California | 2021/05/25 20:15 | Julian Steinhausen v Colton Smith | 2-6,6-3,6-7 |
| UTR Pro Tennis Series California | 2021/05/24 15:00 | Julian Steinhausen v Sema Pankin | 6-1,6-1 |
| UTR Pro Tennis Series California | 2021/05/23 21:00 | Julian Steinhausen v Oleksiy Arovin | 6-2,5-4 |