| Challenger Fairfield | 10/12 17:00 | 26 | [91] Ernesto Escobedo v Klahn, Bradley [313] | 4-6,7-6,3-6 | |
| Challenger Fairfield | 10/10 21:15 | 25 | [313] Klahn, Bradley v King, Kevin [215] | 1-6,6-1,6-1 | |
| Monterrey, Mexico | 10/08 21:15 | 29 | [429] Klahn, Bradley v Maximilian Marterer [132] | 6-7,6-7 | |
| Monterrey, Mexico | 10/07 19:45 | 28 | [429] Klahn, Bradley v Quentin Halys [124] | 7-5,7-6 | |
| Monterrey, Mexico | 10/06 20:50 | 27 | [81] Estrella Burgos, Victor v Klahn, Bradley [429] | 2-6,6-4,4-6 | |
| Monterrey, Mexico | 10/06 01:25 | 26 | [268] Krajicek, Austin v Klahn, Bradley [429] | 6-4,6-7,3-6 | |
| Monterrey, Mexico | 10/03 18:00 | 25 | [429] Klahn, Bradley v Novikov, Dennis [217] | Retired | |
| Challenger - Gwangju | 09/20 01:30 | 26 | [447] Klahn, Bradley v Tatsuma Ito [162] | 5-7,6-1,3-6 | |
| Challenger - Gwangju | 09/19 03:45 | 25 | [298] Chen, Ti v Klahn, Bradley [447] | 2-6,2-6 | |
| Challenger Shanghai | 09/12 02:00 | 25 | [447] Klahn, Bradley v Tatsuma Ito [165] | 6-3,2-6,6-7 | |
| US Open, New York, USA, Qualifying | 08/24 15:00 | 45 | [475] Klahn, Bradley v Guido Andreozzi [150] | 4-6,7-6,4-6 | |
| US Open, New York, USA, Qualifying | 08/22 18:05 | 44 | [475] Klahn, Bradley v Marc Polmans [236] | 6-2,0-6,6-2 | |
| Gatineau, Canada | 07/18 16:00 | 25 | [471] Klahn, Bradley v Schnur, Brayden [213] | 3-6,6-7 | |
| Winnetka, USA | 07/11 15:00 | 25 | [184] Ramkumar Ramanathan v Klahn, Bradley [497] | 3-6,7-6,7-6 | |
| Wimbledon Qual | 06/28 16:40 | 45 | [119] Darian King v Klahn, Bradley [490] | 3-6,6-1,6-4 | |
| Wimbledon Qual | 06/26 10:00 | 44 | [490] Klahn, Bradley v Kwon, S. [192] | 6-3,6-4 | |
| Challenger Vicenza Qual | 05/27 12:50 | 45 | [213] Arevalo-Gonzalez, Marcelo v Klahn, Bradley [477] | 7-5,6-4 | |
| French Open Qual | 05/24 15:20 | 45 | [477] Klahn, Bradley v Fratangelo, Bjorn [138] | 4-6,6-7 | |
| French Open Qual | 05/22 12:35 | 44 | [477] Klahn, Bradley v Smith, John-Patrick [223] | 6-2,6-3 | |
| Challenger Heilbronn Qual | 05/14 09:00 | 46 | [473] Klahn, Bradley v Sebastian Fanselow [337] | 5-7,6-7 | |
| Challenger Heilbronn Qual | 05/13 08:00 | 45 | [393] Bernabe Zapata Miralles v Klahn, Bradley [473] | 6-7,1-6 | |
| Challenger - Tallahassee | 04/27 23:20 | 27 | [267] Arnaboldi, Andrea v Klahn, Bradley [478] | 6-2,7-6 | |
| Challenger - Tallahassee | 04/26 15:00 | 26 | [395] Dominik Koepfer v Klahn, Bradley [478] | 5-7,1-6 | |
| Challenger - Tallahassee | 04/24 18:35 | 25 | [478] Klahn, Bradley v Gonzalez, Maximo [152] | 7-6,6-7,6-4 | |
| Sarasota, USA, Qualifying | 04/16 16:40 | 46 | [474] Klahn, Bradley v Daniel Elahi Galan [393] | 6-7,5-7 | |
| Sarasota, USA, Qualifying | 04/15 15:20 | 45 | Klahn, Bradley v Oljaca, Mark | 6-3,6-3 | |
| ATP Houston Qual | 04/09 16:00 | 46 | [475] Klahn, Bradley v Noah Rubin [182] | 2-6,6-3,6-7 | |
| ATP Houston Qual | 04/08 15:00 | 45 | [96] Renzo Olivo v Klahn, Bradley [475] | Retired | |
| Challenger Panama City | 04/04 18:40 | 25 | [475] Klahn, Bradley v Arnaboldi, Andrea [307] | 2-6,5-7 | |
| ITF USA F11 | 03/26 20:00 | 29 | Sebastian Fanselow v Klahn, Bradley | 6-3,6-2 |