Results
| Challenger Champaign | 11/12 21:05 | 25 | [179] Patrick Kypson v Stefan Kozlov [346] | 1-6,7-6,6-4 | |
| Challenger Sioux Falls | 10/24 23:20 | 26 | Murphy Cassone v Stefan Kozlov | Walkover | |
| Challenger Sioux Falls | 10/22 00:20 | 25 | [350] Stefan Kozlov v Dmitry Popko [175] | 7-6,4-6,6-4 | |
| Challenger Lincoln | 08/06 18:05 | 25 | [360] Stefan Kozlov v Nishesh Basavareddy [295] | 6-2,4-6,2-6 | |
| Challenger Lincoln | 08/05 17:45 | 19 | [360] Stefan Kozlov v Ernesto Escobedo [439] | 6-3,6-1 | |
| Challenger Lincoln | 08/04 18:50 | 14 | Stefan Kozlov v Collin Altamirano | 6-4,7-6 | |
| Challenger Lexington | 07/30 17:40 | 25 | [238] Bernard Tomic v Stefan Kozlov [367] | 6-4,3-6,6-3 | |
| Challenger Lexington | 07/29 20:40 | 19 | Stefan Kozlov v Stefan Dostanic | 7-6,0-6,7-5 | |
| Challenger Lexington | 07/28 15:35 | 14 | [365] Stefan Kozlov v Ryuki Matsuda [318] | 6-2,6-3 | |
| Challenger Chicago | 07/21 16:50 | 14 | Stefan Kozlov v Aidan Mayo | CANC | |
| Challenger Granby | 07/17 14:00 | 25 | [381] Stefan Kozlov v Nicolas Mejia [256] | 1-6,2-6 | |
| Challenger Granby | 07/15 14:00 | 19 | Cooper Williams v Stefan Kozlov | 1-6,6-7 |
Wikipedia - Stefan Kozlov
Stefan Kozlov (Russian: Стефан Козлов, STEF-ahn KOZ-lov; born February 1, 1998) is an American professional tennis player of Russian descent. He has a career-high ATP ranking of world No. 103 achieved on 18 July 2022 and doubles ranking of world No. 180 on 19 June 2017.
Kozlov made his ATP World Tour debut as a wildcard in 2013 Hall of Fame Tennis Championships at the age of 15. He reached two junior Grand Slam finals in 2014 and finished the year at World No. 3 in the ITF Junior Combined rankings.