| Challenger Fergana | 06/18 10:55 | 25 | Farrukh Dustov v Yannick Mertens | 6-4,4-6,6-3 | |
| ATP Lyon Qual | 05/19 08:30 | 64 | [104] Laslo Djere v Yannick Mertens [342] | 6-4,6-3 | |
| Challenger Glasgow | 05/02 11:40 | 25 | [345] Yannick Mertens v Hiroki Moriya [278] | 4-6,6-3,6-7 | |
| ITF Tunisia F16 | 04/29 09:00 | 29 | [339] Yannick Mertens v Altug Celikbilek [487] | 7-6,3-6,4-6 | |
| ITF Tunisia F16 | 04/28 09:00 | 28 | Yannick Mertens v Aidan Mchugh | 6-2,6-1 | |
| ITF Tunisia F16 | 04/27 10:50 | 27 | Yannick Mertens v Damien Bayard | 4-6,6-0,6-3 | |
| ITF Tunisia F16 | 04/26 11:00 | 26 | Yannick Mertens v Peter Bothwell | 6-0,6-4 | |
| ITF Tunisia F16 | 04/25 10:45 | 25 | Yannick Mertens v Skyler Butts | 6-1,6-2 | |
| ITF USA F10 | 04/11 17:10 | 25 | Yannick Mertens v Michael Redlicki | 3-6,3-6 | |
| ITF USA F9 | 04/05 15:00 | 26 | Karue Sell v Yannick Mertens | 6-3,4-6,7-5 | |
| ITF USA F9 | 04/03 15:40 | 25 | Or Ram-Harel v Yannick Mertens | 4-6,6-3,1-6 | |
| Challenger Le Gosier | 03/27 20:55 | 25 | [326] Yannick Mertens v Ruben Bemelmans [116] | 5-7,1-6 | |
| Challenger Lille | 03/20 18:05 | 25 | [420] Guillermo Olaso v Yannick Mertens [326] | 5-7,6-1,6-3 | |
| ITF Israel F1 | 03/09 08:00 | 28 | Yannick Mertens v David Poljak | Retired | |
| ITF Israel F1 | 03/08 08:00 | 27 | Yannick Mertens v Gianluca Mager | 7-5,6-3 | |
| ITF Israel F1 | 03/07 09:40 | 26 | Yannick Mertens v Nicolas Ferrando | 6-2,6-2 | |
| ITF Israel F1 | 03/06 11:35 | 25 | Yannick Mertens v Patrik Niklas-Salminen | 6-3,6-3 | |
| ITF Portugal F1 | 02/24 13:05 | 28 | Yannick Mertens v Tiago Cacao | 3-6,6-4,4-6 | |
| ITF Portugal F1 | 02/23 11:25 | 27 | Yannick Mertens v Igor Marcondes | 3-6,6-4,6-1 | |
| ITF Portugal F1 | 02/22 15:05 | 26 | Yannick Mertens v Jaime Fermosell | 7-5,6-2 | |
| ITF Portugal F1 | 02/20 11:45 | 25 | Yannick Mertens v Fernando Bogajo | 7-6,6-1 | |
| ITF Great Britain F3 | 02/13 12:15 | 25 | Evan Furness v Yannick Mertens | 4-6,7-5,6-4 | |
| ITF Great Britain F1 | 02/04 11:00 | 29 | Scott Griekspoor v Yannick Mertens | 6-1,7-6 | |
| ITF Great Britain F1 | 02/03 10:00 | 28 | Yannick Mertens v Matteo Viola | 7-6,6-1 | |
| ITF Great Britain F1 | 02/02 10:00 | 27 | Neil Pauffley v Yannick Mertens | 6-7,4-6 | |
| ITF Great Britain F1 | 02/01 13:40 | 26 | Nicolas Rosenzweig v Yannick Mertens | 0-6,6-3,4-6 | |
| ITF Great Britain F1 | 01/31 13:45 | 25 | Aidan Mchugh v Yannick Mertens | 6-7,2-6 | |
| ITF Egypt F2 | 01/24 11:10 | 25 | Artem Smirnov v Yannick Mertens | 6-7,6-1,7-5 | |
| ITF Egypt F1 | 01/21 08:00 | 29 | Aslan Karatsev v Yannick Mertens | 6-1,6-2 | |
| ITF Egypt F1 | 01/20 08:00 | 28 | Hiroki Moriya v Yannick Mertens | 4-6,7-5,3-6 |