| Challenger Ortisei | 10/23 13:30 | 14 | Evgeny Karlovskiy v Lukas Lacko | Retired | |
| Challenger Ismaning | 10/09 17:55 | 14 | [342] Bu Yunchaokete v Lukas Lacko [495] | 3-6,6-2,6-3 | |
| Challenger Mallorca | 08/30 09:45 | 19 | Lukas Lacko v Daniil Glinka | Retired | |
| Challenger Mallorca | 08/29 09:50 | 14 | [327] Lukas Lacko v Alexander Donski [291] | 6-4,6-4 | |
| Challenger Malaga | 06/28 10:45 | 25 | [405] Roberto Marcora v Lukas Lacko [301] | 4-6,6-4,6-4 | |
| Wimbledon | 06/20 11:05 | 14 | [187] Andrej Martin v Lukas Lacko [296] | 6-2,6-1 | |
| Challenger Ilkley | 06/13 10:00 | 19 | [238] Lukas Lacko v Rinky Hijikata [230] | 6-3,3-6,4-6 | |
| Challenger Ilkley | 06/12 13:25 | 14 | [204] Alexander Ritschard v Lukas Lacko [242] | 3-6,2-6 | |
| Challenger Nottingham | 06/06 16:40 | 25 | [100] Alexei Popyrin v Lukas Lacko [242] | 6-4,6-2 | |
| Challenger Prostejov | 05/31 11:50 | 25 | Lukas Lacko v Lukas Pokorny | Cancelled | |
| Challenger Troisdorf | 05/24 14:45 | 25 | [386] Aldin Setkic v Lukas Lacko [229] | 4-6,6-3,6-4 | |
| French Open | 05/17 08:00 | 14 | [229] Lukas Lacko v Nicolas Jarry [138] | 6-7,3-6 | |
| Challenger Zagreb | 05/10 11:45 | 25 | [225] Lukas Lacko v Filip Misolic [301] | 4-6,1-6 | |
| Challenger Mauthausen | 05/02 15:10 | 25 | [157] Jurij Rodionov v Lukas Lacko [224] | 6-1,6-0 | |
| Challenger Ostrava | 04/26 13:50 | 25 | [278] Evan Furness v Lukas Lacko [220] | 6-1,6-1 | |
| Challenger Forli | 02/22 11:35 | 25 | [132] Tomas Machac v Lukas Lacko [207] | 6-2,6-2 | |
| ATP Marseille | 02/13 10:00 | 14 | [252] Andrea Arnaboldi v Lukas Lacko [206] | 7-6,6-4 | |
| ATP Montpellier | 01/30 13:10 | 14 | Lukas Lacko v Antoine Hoang | 6-7,2-6 | |
| ATP Montpellier | 01/30 13:10 | 14 | [188] Lukas Lacko v Mats Moraing [156] | Cancelled | |
| Challenger Quimper | 01/27 17:00 | 27 | [138] Vasek Pospisil v Lukas Lacko [188] | 6-4,6-3 | |
| Challenger Quimper | 01/25 17:05 | 25 | [156] Mats Moraing v Lukas Lacko [188] | 3-6,5-7 | |
| Challenger Forli | 01/18 14:40 | 25 | [221] Andrea Pellegrino v Lukas Lacko [188] | 0-6,6-3,7-6 | |
| Australian Open | 01/09 23:00 | 14 | [199] Marco Trungelliti v Lukas Lacko [190] | 6-3,6-4 | |
| Czech Extraliga | 12/14 10:20 | - | Dominik Kellovsky v Lukas Lacko | 4-6,4-6 | |
| Czech Extraliga | 12/13 11:40 | - | [142] Zdenek Kolar v Lukas Lacko [190] | 6-3,7-5 | |
| Challenger Bratislava | 11/11 17:20 | 26 | [195] Lukas Lacko v Zsombor Piros [340] | 2-6,4-6 | |
| Challenger Bratislava | 11/10 13:50 | 25 | Milos Karol v Lukas Lacko | 4-6,3-6 | |
| Challenger Eckental | 11/03 09:00 | 25 | Ramkumar Ramanathan v Lukas Lacko | Cancelled | |
| Challenger Ismaning | 10/31 13:00 | 29 | [212] Lukas Lacko v Oscar Otte [135] | 4-6,4-6 | |
| Challenger Ismaning | 10/30 14:10 | 28 | [148] Quentin Halys v Lukas Lacko [212] | 1-6,6-7 |