Stefan Kozlov (#no-rank)
| atpworldtour.com | ATP | Country |  United States of America |
| Wikipedia | Eng / Fr | Birth | - |
| Career best ranking | 103 - 2022-07-18 | Résidence |  Unknown |
| Height | - | ||
| Weight | - |
| Conditions | W | D | ratio |
|---|---|---|---|
| Grass | 3 | 6 | 33.33% |
| Hard (in.) | 6 | 3 | 66.67% |
| Hard (out.) | 4 | 12 | 25.00% |
| Clay | 0 | 3 | 0.00% |
| TOTAL | 13 | 24 | 35.14% |
| # | Date | Categ | Tournament | Conditions | Round | #Rank | Opponent | Score | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 2025-07-07 | Challenger | Newport HOF Open | Grass | 16e | #367 | #158 Mitchell Krueger | 6/1 3/6 6/1 | |
| 2 | 2025-01-20 | Challenger |  Challenger Quimper | Hard (in.) | 16e | #10000 |  #154 Elmer Moller | 6/3 7/5 | |
| 3 | 2024-01-29 | Challenger | Cleveland Open | Hard (in.) | 8e | #722 | #334 Ethan Quinn | 6/2 4/6 6/3 | |
| 4 | 2024-01-29 | Challenger | Cleveland Open | Hard (in.) | 16e | #722 | #417 Strong Kirchheimer | 3/6 6/1 7/6(3) | |
| 5 | 2022-09-19 | 250 | San Diego Open | Hard (out.) | 16e | #111 | #87 Jeffrey John Wolf | 6/2 7/6(6) | |
| 6 | 2022-08-29 | GS | US Open | Hard (out.) | 64e | #110 |  #1 Daniil Medvedev | 6/2 6/4 6/0 | |
| 7 | 2022-08-01 | 500 | Washington Open | Hard (out.) | 32e | #113 |  #85 Jack Draper | 7/5 6/2 | |
| 8 | 2022-07-11 | 250 | Newport HOF Open | Grass | 16e | #107 | #93 Steve Johnson | 7/5 6/3 | |
| 9 | 2022-06-27 | GS | Wimbledon | Grass | 64e | #107 |  #16 Diego Schwartzman | 6/3 6/2 6/2 | |
| 10 | 2022-05-30 | Challenger | Surbiton Trophy Challenger | Grass | 8e | #113 | #75 Brandon Nakashima | 6/4 6/3 | |
| 11 | 2022-05-30 | Challenger | Surbiton Trophy Challenger | Grass | 16e | #113 |  #116 Mats Moraing | 6/3 7/6(4) | |
| 12 | 2022-04-25 | Challenger | Savannah Challenger | Clay | 16e | #123 |  #531 Jose Pereira | 6/1 6/0 | |
| 13 | 2022-04-04 | Challenger |  Mexico City Open Challenger | Clay | 16e | #122 |  #270 Gerald Melzer | 6/4 ret. | |
| 14 | 2022-02-21 | 500 | Mexican Open | Hard (out.) | 8e | #130 |  #5 Rafael Nadal | 6/0 6/3 | |
| 15 | 2022-02-21 | 500 | Mexican Open | Hard (out.) | 16e | #130 |  #33 Grigor Dimitrov | 7/6(8) 5/7 6/3 | |
| 16 | 2022-02-14 | 250 | Delray Beach Open | Hard (out.) | QF | #151 | #43 Tommy Paul | 6/3 6/1 | |
| 17 | 2022-02-14 | 250 | Delray Beach Open | Hard (out.) | 8e | #151 | #93 Steve Johnson | 6/1 6/3 | |
| 18 | 2022-02-14 | 250 | Delray Beach Open | Hard (out.) | 16e | #151 |  #149 Emilio Gomez | 4/6 7/5 6/3 | |
| 19 | 2022-01-17 | GS |  Australian Open | Hard (out.) | 32e | #168 |  #7 Matteo Berrettini | 6/1 4/6 6/4 6/1 | |
| 20 | 2022-01-17 | GS | Australian Open | Hard (out.) | 64e | #168 |  #79 Jiri Vesely | 7/5 6/3 6/4 | |
| 21 | 2021-09-20 | Challenger | Ohio Championships Challenger | Hard (in.) | F | #301 | #200 Max Purcell | 4/6 6/2 6/4 | |
| 22 | 2021-09-20 | Challenger | Ohio Championships Challenger | Hard (in.) | DF | #301 | #178 J.J. Wolf | 2/6 6/3 7/5 | |
| 23 | 2021-09-20 | Challenger | Ohio Championships Challenger | Hard (in.) | QF | #301 | #213 Mikael Torpegaard | 2/6 7/6(4) 6/4 | |
| 24 | 2021-09-20 | Challenger | Ohio Championships Challenger | Hard (in.) | 8e | #301 | #217 Jason Kubler | 6/2 7/5 | |
| 25 | 2021-09-20 | Challenger | Ohio Championships Challenger | Hard (in.) | 16e | #301 | #182 Mitchell Krueger | 6/0 6/3 | |
| 26 | 2021-03-15 | 500 | Mexican Open | Hard (out.) | 16e | #389 | #63 Cameron Norrie | 6/3 6/3 | |
| 27 | 2020-02-17 | 250 | Delray Beach Open | Hard (out.) | 16e | #367 | #43 Ugo Humbert | 6/7(5) 6/3 6/1 | |
| 28 | 2018-04-09 | 250 | U.S. Men's Clay Court Championship | Clay | 16e | #182 | #63 Guido Pella | 6/3 6/2 | |
| 29 | 2017-08-14 | 1000 | Cincinnati Masters | Hard (out.) | 32e | #132 | #20 Sam Querrey | 6/3 6/0 | |
| 30 | 2017-07-24 | 250 | Atlanta Open | Hard (out.) | 16e | #133 | #134 Quentin Halys | 7/5 7/6(7) | |
| 31 | 2017-06-19 | 500 | Tournoi du Queen's | Grass | 8e | #150 |  #7 Marin Cilic | 6/0 6/4 | |
| 32 | 2017-06-19 | 500 | Tournoi du Queen's | Grass | 16e | #150 | #25 Steve Johnson | 3/6 6/1 6/1 | |
| 33 | 2017-06-12 | 250 |  's-Hertogenbosch | Grass | 8e | #144 | #24 Ivo Karlovic | 6/4 6/1 | |
| 34 | 2017-06-12 | 250 | 's-Hertogenbosch | Grass | 16e | #144 | #76 Dustin Brown | 6/3 3/6 6/3 | |
| 35 | 2017-03-09 | 1000 | Indian Wells Masters | Hard (out.) | 64e | #116 | #60 Donald Young | 7/5 7/6(5) | |
| 36 | 2017-02-27 | 500 | Mexican Open | Hard (out.) | 16e | #115 | #113 Ernesto Escobedo | 6/1 2/6 6/0 | |
| 37 | 2014-10-20 | 500 | Valence Open | Hard (in.) | 16e | #444 |  #37 Martin Klizan | 6/3 6/3 |
LLTL
ATP
WTA/Double
Yearly
Race
attente
<=
=>
RookiesLeaderotron
Mega Patate
Big Lose
Clay 
Grass 
Hard indoor 
Hard outdoor 
attente