| Wimbledon | 06/28 15:40 | 23 | [107] Stefan Kozlov v Diego Schwartzman [15] | 3-6,2-6,2-6 | |
| Wimbledon | 06/23 10:00 | 19 | [107] Stefan Kozlov v Dennis Novak [155] | 5-7,4-6,7-5,6-3,3-6 | |
| Wimbledon | 06/22 10:00 | 19 | [107] Stefan Kozlov v Dominic Stephan Stricker [188] | 7-6,4-6,6-3 | |
| Wimbledon | 06/20 12:15 | 14 | [107] Stefan Kozlov v Evan Furness [229] | 7-5,6-3 | |
| ATP Queens | 06/11 11:20 | 26 | [111] Stefan Kozlov v Steve Johnson [87] | 0-6,0-6 | |
| ATP Hertogenbosch | 06/04 11:00 | 14 | [112] Stefan Kozlov v Matthew Ebden [395] | 4-6,4-6 | |
| Challenger Surbiton | 06/02 10:00 | 26 | [112] Stefan Kozlov v Brandon Nakashima [75] | 4-6,3-6 | |
| Challenger Surbiton | 06/01 13:55 | 25 | [113] Stefan Kozlov v Mats Moraing [116] | 6-3,7-6 | |
| French Open | 05/17 16:00 | 14 | [116] Stefan Kozlov v Nino Serdarusic [188] | 5-7,0-6 | |
| Challenger Bordeaux | 05/10 15:00 | 25 | [94] Jaume Munar v Stefan Kozlov [118] | 6-2,6-3 | |
| Challenger Savannah | 04/26 21:30 | 25 | Jose Pereira v Stefan Kozlov | 6-1,6-0 | |
| Challenger Mexico City | 04/04 21:55 | 25 | [271] Gerald Melzer v Stefan Kozlov [122] | Retired |