Stadium: Indoor 5 Round: 26 Ground: Hardcourt outdoor
| Challenger Seoul | 2018/05/01 07:05 | Tatsuma Ito v Duckhee Lee | 6-1,6-3 |
| Challenger Kobe | 2017/11/07 04:25 | Duckhee Lee v Tatsuma Ito | 2-6,1-6 |
| Challenger Gimcheon | 2017/05/02 05:55 | Tatsuma Ito v Duckhee Lee | 6-4,3-6,4-6 |
| Challenger Shenzhen | 2017/03/14 06:00 | Duckhee Lee v Tatsuma Ito | 6-1,5-7,6-4 |
| Challenger Kaohsiung | 2015/09/21 07:40 | Tatsuma Ito v Duckhee Lee | 4-6,7-6,6-3 |
| Challenger Liuzhou | 2018/10/24 03:00 | Di Wu v Tatsuma Ito | 6-3,6-4 |
| Challenger Liuzhou | 2018/10/23 02:00 | Sumit Nagal v Tatsuma Ito | 2-6,3-6 |
| Challenger Ningbo | 2018/10/19 06:40 | Tatsuma Ito v Radu Albot | 5-7,4-6 |
| Challenger Ningbo | 2018/10/18 03:00 | Tatsuma Ito v Rigele Te | 6-4,6-4 |
| Challenger Ningbo | 2018/10/16 10:00 | Tatsuma Ito v Yusuke Takahashi | 7-6,6-3 |
| ATP Tokyo | 2018/09/30 03:50 | Tatsuma Ito v Yosuke Watanuki | 2-6,4-6 |
| ATP Tokyo | 2018/09/29 04:45 | Mackenzie McDonald v Tatsuma Ito | 4-6,6-1,3-6 |
| ATP Shenzhen | 2018/09/25 12:15 | Tatsuma Ito v Taro Daniel | 6-2,5-7,6-7 |
| Challenger Liuzhou | 2018/10/24 06:00 | Radu Albot v Duckhee Lee | 6-2,7-5 |
| Challenger Liuzhou | 2018/10/22 04:15 | Duckhee Lee v Tsung-Hua Yang | 6-2,6-3 |
| Challenger Tashkent | 2018/10/08 14:10 | Evgeny Karlovskiy v Duckhee Lee | 7-6,6-4 |
| Challenger Kaohsiung | 2018/09/22 08:10 | Gael Monfils v Duckhee Lee | 6-1,6-1 |
| Challenger Kaohsiung | 2018/09/21 12:05 | Duckhee Lee v Frederico Ferreira Silva | 6-2,7-5 |
| Challenger Kaohsiung | 2018/09/20 10:00 | Jason Jung v Duckhee Lee | 6-7,4-6 |
| Challenger Kaohsiung | 2018/09/19 08:50 | Tomislav Brkic v Duckhee Lee | 2-6,6-7 |
| Davis Cup | 2018/09/15 03:35 | Duckhee Lee v Rubin Statham | 6-4,6-1 |