| ATP Stockholm | 10/16 13:45 | 25 | [81] Lukas Lacko v Taro Daniel [69] | 6-1,6-4 | |
| Challenger Ortisei | 10/09 14:25 | 25 | [338] Ante Pavic v Lukas Lacko [80] | 7-6,7-6 | |
| ATP Shenzhen | 09/25 12:00 | 25 | [77] Lukas Lacko v Mackenzie McDonald [80] | Retired | |
| ATP St Petersburg | 09/20 13:20 | 26 | [22] Marco Cecchinato v Lukas Lacko [77] | 7-5,7-6 | |
| ATP St Petersburg | 09/18 15:30 | 25 | [109] Ruben Bemelmans v Lukas Lacko [77] | 2-6,6-4,5-7 | |
| ATP St Petersburg | 09/18 15:30 | 25 | Marcos Baghdatis v Lukas Lacko | Cancelled | |
| US Open | 08/27 21:40 | 23 | [88] Vasek Pospisil v Lukas Lacko [77] | 7-5,6-3,6-2 | |
| ATP Winston-Salem | 08/20 21:15 | 24 | [149] Horacio Zeballos v Lukas Lacko [77] | 7-6,7-5 | |
| ATP Washington | 07/31 20:55 | 24 | [75] Lukas Lacko v Denis Kudla [85] | 7-6,1-6,4-6 | |
| ATP Atlanta | 07/25 17:00 | 26 | [53] Ryan Harrison v Lukas Lacko [71] | 2-6,6-2,6-3 | |
| ATP Atlanta | 07/23 19:40 | 25 | [71] Lukas Lacko v Prajnesh Gunneswaran [186] | 6-2,6-2 | |
| Wimbledon | 07/04 13:30 | 24 | [2] Roger Federer v Lukas Lacko [73] | 6-4,6-4,6-1 | |
| Wimbledon | 07/02 17:00 | 23 | [73] Lukas Lacko v Benjamin Bonzi [284] | 4-6,6-3,7-6,6-4 | |
| ATP Eastbourne | 06/30 14:00 | 29 | [94] Lukas Lacko v Mischa Zverev [67] | 4-6,4-6 | |
| ATP Eastbourne | 06/29 14:50 | 28 | [94] Lukas Lacko v Marco Cecchinato [31] | 6-3,6-4 | |
| ATP Eastbourne | 06/28 10:00 | 27 | [94] Lukas Lacko v Cameron Norrie [79] | 6-3,6-4 | |
| ATP Eastbourne | 06/27 11:15 | 26 | [11] Diego Schwartzman v Lukas Lacko [94] | 6-4,4-6,5-7 | |
| ATP Eastbourne | 06/26 11:20 | 25 | [244] Roberto Quiroz v Lukas Lacko [94] | 4-6,6-7 | |
| ATP Halle | 06/18 12:45 | 25 | [96] Lukas Lacko v Denis Kudla [109] | 4-6,4-6 | |
| ATP Halle Qual | 06/17 09:00 | 164 | [135] Yannick Maden v Lukas Lacko [94] | 2-6,3-6 | |
| ATP Halle Qual | 06/16 09:00 | 64 | [94] Lukas Lacko v Ivo Karlovic [90] | 7-6,7-6 | |
| ATP Stuttgart Qual | 06/09 09:00 | 64 | [99] Lukas Lacko v Tim Puetz [305] | 7-6,5-7,1-6 | |
| Challenger Surbiton | 06/07 10:00 | 26 | [113] Denis Kudla v Lukas Lacko [99] | 6-4,6-0 | |
| Challenger Surbiton | 06/04 14:35 | 25 | [186] Dennis Novikov v Lukas Lacko [99] | 6-4,1-6,5-7 | |
| Challenger Loughborough | 05/23 11:00 | 25 | [100] Lukas Lacko v Yosuke Watanuki [283] | 3-6,5-7 | |
| Challenger Glasgow | 05/06 12:00 | 29 | [104] Lukas Lacko v Luca Vanni [314] | 4-6,7-6,6-4 | |
| Challenger Glasgow | 05/05 10:00 | 28 | [104] Lukas Lacko v David Guez [284] | 6-3,6-4 | |
| Challenger Glasgow | 05/04 09:30 | 27 | [104] Lukas Lacko v Guillermo Olaso [386] | 6-2,6-3 | |
| Challenger Glasgow | 05/03 12:00 | 26 | [104] Lukas Lacko v Hiroki Moriya [278] | 6-1,6-4 | |
| Challenger Glasgow | 05/02 12:30 | 25 | [104] Lukas Lacko v Joris De Loore [322] | 6-4,6-4 |