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