Challenger Charlottesville 11/01 21:50 25 [199] Mitchell Krueger v Stefan Kozlov [132] 5-7,6-0,6-7
Challenger Las Vegas 10/30 19:00 29 [444] Tennys Sandgren v Stefan Kozlov [133] 7-5,6-3
Challenger Las Vegas 10/29 19:55 28 [133] Stefan Kozlov v Steve Johnson [119] 6-3,1-6,7-5
Challenger Las Vegas 10/28 19:10 27 [225] Alexis Galarneau v Stefan Kozlov [133] 7-6,4-6,3-6
Challenger Las Vegas 10/27 18:00 26 [321] Evan Zhu v Stefan Kozlov [133] 6-7,2-6
Challenger Las Vegas 10/25 19:40 25 Cannon Kingsley v Stefan Kozlov 5-7,6-4,1-6
Challenger Fairfield 10/11 18:20 25 Riffice, Sam v Stefan Kozlov 3-6,6-2,6-3
Challenger Tiburon 10/06 19:35 26 [243] Alexis Galarneau v Stefan Kozlov [130] 6-1,7-5
Challenger Tiburon 10/04 19:45 25 [361] Giovanni Oradini v Stefan Kozlov [130] 1-6,4-6
Charleston, SC, USA 09/27 14:00 25 Evan Zhu v Stefan Kozlov Cancelled
San Diego, USA 09/20 00:30 25 [73] Wolf, Jeffrey John v Stefan Kozlov [108] 6-2,7-6
Challenger Cary 09/15 20:00 26 [307] Yasutaka Uchiyama v Stefan Kozlov [110] Retired
Challenger Cary 09/13 18:00 25 Cannon Kingsley v Stefan Kozlov 6-2,2-6,2-6
US Open, New York, USA 08/29 16:00 23 [1] Daniil Medvedev v Stefan Kozlov [111] 6-2,6-4,6-0
Challenger Granby 08/23 14:00 25 Stefan Kozlov v Aidan Mchugh Cancelled
Cincinnati, USA 08/13 20:15 14 [113] Stefan Kozlov v Dusan Lajovic [68] 3-6,5-7
Challenger Chicago 08/10 18:50 25 [113] Stefan Kozlov v Ernesto Escobedo [174] 4-6,6-7
Washington, USA 08/01 21:20 24 [111] Stefan Kozlov v Jack Draper [81] 5-7,2-6
Atlanta, USA 07/23 18:00 26 [196] Ramkumar Ramanathan v Stefan Kozlov [103] 6-0,6-1
Challenger Indianapolis 07/18 22:45 25 [269] Aleksandar Kovacevic v Stefan Kozlov [103] 6-3,6-7,6-4
Newport, USA 07/11 18:40 25 [104] Stefan Kozlov v Steve Johnson [95] 5-7,3-6
Wimbledon, London, Great Britain 06/28 15:40 23 [107] Stefan Kozlov v Diego Schwartzman [15] 3-6,2-6,2-6
Wimbledon, London, Great Britain 06/23 10:00 19 [107] Stefan Kozlov v Dennis Novak [155] 5-7,4-6,7-5,6-3,3-6
Wimbledon, London, Great Britain 06/22 10:00 19 [107] Stefan Kozlov v Stricker, Dominic Stephan [188] 7-6,4-6,6-3
Wimbledon, London, Great Britain 06/20 12:15 14 [107] Stefan Kozlov v Evan Furness [229] 7-5,6-3
London, Great Britain 06/11 11:20 26 [111] Stefan Kozlov v Steve Johnson [87] 0-6,0-6
s-Hertogenbosch, Netherlands 06/04 11:00 14 [112] Stefan Kozlov v Ebden, Matthew [395] 4-6,4-6
Surbiton, Great Britain 06/02 10:00 26 [112] Stefan Kozlov v Brandon Nakashima [75] 4-6,3-6
Surbiton, Great Britain 05/30 16:10 25 [113] Stefan Kozlov v Moraing, Mats [116] 6-3,7-6
Open de France 05/17 16:00 14 [116] Stefan Kozlov v Nino Serdarusic [188] 5-7,0-6

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.