| Stuttgart, Germany | 06/13 09:00 | 25 | [79] Kuznetsov, Andrey v Janowicz, Jerzy [155] | 4-6,6-3,3-6 | |
| Prostejov, Czech Republic | 06/06 10:40 | 25 | [274] 로브레도, 토미 v Janowicz, Jerzy [164] | 3-6,6-4,7-6 | |
| French Open, Paris, France | 05/28 11:25 | 23 | [102] 다니엘, 타로 v Janowicz, Jerzy [164] | 6-4,6-4,6-4 | |
| ATP Madrid Qual | 05/06 13:45 | 45 | Janowicz, Jerzy v 헤르벨트, 피에레-후구에스 | 6-7,2-6 | |
| ATP Munich Qual | 04/30 10:00 | - | [322] 스테브, 세드릭-마르셀 v Janowicz, Jerzy [165] | 7-6,6-2 | |
| ATP Munich Qual | 04/29 10:00 | - | [376] 바친겔, 마티아스 v Janowicz, Jerzy [165] | 4-6,6-4,3-6 | |
| Challenger Leon | 03/29 16:00 | 25 | 하치 베르두고, 한스 v Janowicz, Jerzy | Cancelled | |
| Challenger Guadalajara | 03/26 02:00 | 28 | [183] Janowicz, Jerzy v 사포발로브, 데니스 [194] | 6-4,3-6,6-7 | |
| Challenger Guadalajara | 03/25 00:20 | 27 | [183] Janowicz, Jerzy v 산드그렌, 테니스 [161] | 6-4,6-2 | |
| Challenger Guadalajara | 03/24 02:10 | 26 | [183] Janowicz, Jerzy v 코리아, 페데리코 [242] | 6-2,6-1 | |
| Challenger Guadalajara | 03/22 02:05 | 25 | [188] Groth, Sam v Janowicz, Jerzy [183] | 3-6,7-6,1-6 | |
| Challenger Wroclaw | 03/02 17:00 | 26 | Janowicz, Jerzy v 멜저, 주르겐 | 5-7,6-7 | |
| Challenger Wroclaw | 03/01 17:00 | 25 | 잘로비에스, 마크 v Janowicz, Jerzy | 4-6,2-6 | |
| Bergamo, Italy | 02/26 16:00 | 29 | 할리스, 퀸틴 v Janowicz, Jerzy | 4-6,4-6 | |
| Bergamo, Italy | 02/25 19:30 | 28 | 크라지노비치, 필리프 v Janowicz, Jerzy | 3-6,3-6 | |
| Bergamo, Italy | 02/24 18:30 | 27 | Janowicz, Jerzy v 게라시모브, 에고르 | 6-7,6-3,7-5 | |
| Bergamo, Italy | 02/23 20:15 | 26 | Janowicz, Jerzy v 바식, 미르자 | 7-6,6-2 | |
| Bergamo, Italy | 02/22 18:30 | 25 | 마르테어, 맥시밀리안 v Janowicz, Jerzy | 3-6,4-6 | |
| Sofia, Bulgaria | 02/09 16:00 | 26 | 디미트로브, 그리고르 v Janowicz, Jerzy | 4-6,6-3,7-5 | |
| Sofia, Bulgaria | 02/08 13:00 | 25 | Janowicz, Jerzy v 셀라, 두디 | 6-4,6-4 | |
| Challenger Quimper | 02/02 20:05 | 26 | 마나리노, 아드리안 v Janowicz, Jerzy | 6-4,3-6,6-4 | |
| Challenger Quimper | 02/01 14:40 | 25 | 레우터, 야닉 v Janowicz, Jerzy | 2-6,3-6 | |
| Australian Open, Melbourne, Australia | 01/16 03:30 | 23 | Janowicz, Jerzy v 실리크, 마린 | 6-4,6-4,2-6,2-6,3-6 | |
| Kooyong Classic 2020 | 01/11 02:40 | 1 | 니시오카, 요시히토 v Janowicz, Jerzy | 6-7,6-7 | |
| Kooyong Classic 2020 | 01/10 05:00 | 1 | HAAS T. v Janowicz, Jerzy | 7-5,4-6,4-10 | |
| Auckland, New Zealand, Qualifying | 01/08 01:45 | 46 | 모흐, 미켈 v Janowicz, Jerzy | 7-6,6-3 | |
| Auckland, New Zealand, Qualifying | 01/07 02:05 | 45 | Stabins, Krisjanis v Janowicz, Jerzy | 4-6,4-6 | |
| Challenger Mons | 10/05 11:45 | 26 | Janowicz, Jerzy v 베란키스, 리칼다스 | 5-7,6-7 | |
| Challenger Mons | 10/03 12:45 | 25 | 라코, 루카스 v Janowicz, Jerzy | 4-6,4-6 | |
| Orleans, France | 09/27 16:00 | 25 | 로브레도, 토미 v Janowicz, Jerzy | 3-6,6-3,7-5 |