| ATP Stockholm Qual | 10/15 11:15 | 26 | [110] Lacko, Lukas v Galovic, Viktor [234] | 6-4,6-3 | |
| Challenger Kaohsiung | 10/06 07:55 | 27 | [113] Lacko, Lukas v Evgeny Donskoy [89] | 2-6,4-6 | |
| Challenger Kaohsiung | 10/04 03:00 | 26 | Lacko, Lukas v Yan Bai | 7-5,6-2 | |
| Challenger Kaohsiung | 10/02 04:45 | 25 | [118] Lacko, Lukas v Kwon, S. [202] | 6-3,6-4 | |
| ATP Shenzhen | 09/28 13:20 | 26 | [118] Lacko, Lukas v Damir Dzumhur [40] | 4-6,3-6 | |
| ATP Shenzhen | 09/26 10:10 | 25 | [118] Lacko, Lukas v Granollers, Marcel [128] | 6-3,6-4 | |
| Shenzhen, China, Qualifying | 09/24 08:40 | 46 | [117] Lacko, Lukas v Marc Polmans [234] | 6-3,6-4 | |
| Shenzhen, China, Qualifying | 09/23 06:00 | 45 | [117] Lacko, Lukas v Yusuke Takahashi [257] | 6-3,6-4 | |
| US Open, New York, USA | 08/28 17:00 | 23 | [120] Lacko, Lukas v Benoit Paire [41] | 3-6,2-6,6-7 | |
| US Open, New York, USA, Qualifying | 08/25 18:00 | 46 | [120] Lacko, Lukas v Darian King [168] | 6-3,4-6,3-6 | |
| US Open, New York, USA, Qualifying | 08/24 21:05 | 45 | [120] Lacko, Lukas v Krajicek, Austin [292] | 7-6,7-6 | |
| US Open, New York, USA, Qualifying | 08/23 17:40 | 44 | [120] Lacko, Lukas v Grigelis, Laurynas [237] | 6-3,6-4 | |
| Portoroz, Slovénie | 08/08 09:10 | 25 | Lacko, Lukas v Fermosell, Jaime | Retired | |
| Washington, USA | 08/02 03:00 | 25 | [32] DEL POTRO J.M. v Lacko, Lukas [119] | 7-5,6-2 | |
| Washington, USA | 07/31 21:45 | 24 | Halebian, Alexios v Lacko, Lukas | 3-6,4-6 | |
| Atlanta, USA | 07/28 18:10 | 27 | [129] Lacko, Lukas v Isner, John [20] | 5-7,4-6 | |
| Atlanta, USA | 07/26 21:20 | 26 | [51] Young, Donald v Lacko, Lukas [129] | 3-6,1-6 | |
| Atlanta, USA | 07/24 19:10 | 25 | [129] Lacko, Lukas v Fabbiano, Thomas [89] | 6-1,6-2 | |
| Newport, USA | 07/19 19:40 | 26 | [127] Lacko, Lukas v Ebden, Matthew [249] | 1-6,6-7 | |
| Newport, USA | 07/18 16:20 | 25 | [127] Lacko, Lukas v Opelka, Reilly [126] | 7-6,6-4 | |
| Wimbledon Qual | 06/29 13:35 | - | [103] Lacko, Lukas v Gojowczyk, Peter [140] | 5-7,2-6,3-6 | |
| Wimbledon Qual | 06/28 14:50 | 45 | [103] Lacko, Lukas v Arnaboldi, Andrea [258] | 7-6,6-4 | |
| Wimbledon Qual | 06/26 12:40 | 44 | [103] Lacko, Lukas v Hiroki Moriya [186] | 6-3,6-3 | |
| ATP Halle | 06/20 10:00 | 25 | [103] Lacko, Lukas v Zverev, Mischa [29] | 4-6,4-6 | |
| ATP Halle Qual | 06/18 10:00 | 46 | [76] Seppi, Andreas v Lacko, Lukas [109] | 4-6,5-7 | |
| ATP Halle Qual | 06/17 09:00 | 45 | [120] Bemelmans, Ruben v Lacko, Lukas [109] | 4-6,3-6 | |
| Stuttgart, Germany | 06/12 11:30 | 25 | [109] Lacko, Lukas v Jan-Lennard Struff [53] | 4-6,6-7 | |
| ATP Stuttgart Qual | 06/11 08:00 | 46 | [110] Lacko, Lukas v Alexander Bublik [143] | 6-3,7-5 | |
| ATP Stuttgart Qual | 06/10 08:30 | 45 | [110] Lacko, Lukas v Brands, Daniel [198] | 6-3,6-4 | |
| Surbiton, Great Britain | 06/08 15:45 | 26 | [94] Marius Copil v Lacko, Lukas [110] | 6-3,7-6 |