Stadium: Center Court Round: 28 Ground: Carpet indoor
| Challenger Ismaning | 2019/10/18 14:15 | Gabashvili, Teimuraz v Lacko, Lukas | 7-5,4-6,4-6 |
| Challenger Ismaning | 2019/10/17 15:15 | Lacko, Lukas v Baldi, Filippo | 6-1,6-4 |
| Challenger Ismaning | 2019/10/16 14:35 | Lacko, Lukas v Vitaliy Sachko | 7-5,2-6,6-3 |
| US Open, New York, USA | 2019/08/23 15:00 | Kamke, Tobias v Lacko, Lukas | 7-5,6-3 |
| US Open, New York, USA | 2019/08/21 16:30 | Nicola Kuhn v Lacko, Lukas | 4-6,6-7 |
| US Open, New York, USA | 2019/08/19 19:50 | Lacko, Lukas v Maden, Yannick | 6-4,6-3 |
| Vancouver, Canada | 2019/08/12 21:00 | Tim Van Rijthoven v Lacko, Lukas | 6-7,6-4,6-1 |
| Challenger Aptos | 2019/08/08 19:35 | Damir Dzumhur v Lacko, Lukas | 6-7,6-3,7-6 |
| Challenger Ismaning | 2019/10/17 16:35 | Lenz, Julian v Constant Lestienne | 7-6,6-4 |
| Challenger Ismaning | 2019/10/15 11:30 | Lukas Klein v Lenz, Julian | 4-6,3-6 |
| Challenger Ismaning | 2019/10/14 08:00 | Lenz, Julian v Jeremy Schifris | 6-3,6-3 |
| Nur-Sultan II, Kazakhstan | 2019/10/02 09:50 | Istomin, Denis v Lenz, Julian | 7-5,6-1 |
| Nur-Sultan II, Kazakhstan | 2019/10/01 09:00 | Lenz, Julian v Beibit Zhukayev | 6-2,7-6 |
| Orleans, France | 2019/09/24 14:55 | Viktor Durasovic v Lenz, Julian | 6-3,7-6 |
| Metz, France | 2019/09/17 17:45 | Lenz, Julian v Pablo Carreno Busta | 1-6,1-6 |
| Metz, France | 2019/09/16 09:00 | Bachinger, Matthias v Lenz, Julian | 4-6,4-6 |