| Challenger Columbus | 06/13 19:45 | 26 | [218] Duckhee Lee v Sela, Dudi [164] | 3-6,1-6 | |
| Challenger Columbus | 06/12 18:10 | 25 | Duckhee Lee v Mcnally, John | 6-3,7-5 | |
| Little Rock, USA | 06/09 18:50 | 29 | [209] Sela, Dudi v Duckhee Lee [243] | Retired | |
| Little Rock, USA | 06/08 21:00 | 28 | [243] Duckhee Lee v Darian King [200] | 6-0,6-0 | |
| Little Rock, USA | 06/08 16:35 | 27 | [243] Duckhee Lee v Mitchell Krueger [188] | 4-6,6-3,6-1 | |
| Little Rock, USA | 06/07 21:00 | 26 | [328] Zhizhen Zhang v Duckhee Lee [243] | 4-6,7-6,6-7 | |
| Little Rock, USA | 06/05 15:00 | 25 | Arconada, Jordi v Duckhee Lee | 1-6,4-6 | |
| Challenger - Gwangju | 05/15 03:40 | 25 | [241] Duckhee Lee v Yunseong Chung [253] | 4-6,2-6 | |
| Challenger - Busan | 05/09 04:40 | 26 | [95] Ricardas Berankis v Duckhee Lee [247] | 6-3,3-6,6-3 | |
| Challenger - Busan | 05/08 04:50 | 25 | [247] Duckhee Lee v Sugita, Yuichi [181] | 5-7,6-3,7-6 | |
| Challenger - Busan | 05/07 06:20 | 24 | [349] Makoto Ochi v Duckhee Lee [247] | 6-7,4-6 | |
| Challenger Seoul | 04/30 03:35 | 24 | [364] Nam, Ji Sung v Duckhee Lee [246] | 7-5,6-1 | |
| Nanchang, China | 04/24 04:15 | 25 | [236] Duckhee Lee v Goncalo Oliveira [262] | 3-6,2-6 | |
| Taipei, Chinese Taipei | 04/08 03:20 | 24 | [252] Kaichi Uchida v Duckhee Lee [237] | 6-4,6-4 | |
| Challenger - Shenzhen | 03/15 09:00 | 27 | [106] Schnur, Brayden v Duckhee Lee [244] | 6-4,4-6,7-5 | |
| Challenger - Shenzhen | 03/14 10:55 | 26 | [247] Li, Zhe v Duckhee Lee [244] | 3-6,3-6 | |
| Challenger - Shenzhen | 03/12 07:20 | 25 | [244] Duckhee Lee v Sugita, Yuichi [176] | 6-3,6-4 | |
| Challenger - Shenzhen | 03/11 03:50 | 24 | [354] Xia, Zihao v Duckhee Lee [244] | 3-6,1-6 | |
| Challenger Zhuhai | 03/04 05:25 | 24 | [424] Crepatte, Baptiste v Duckhee Lee [244] | 6-3,7-6 | |
| Challenger Yokohama | 03/01 02:00 | 27 | [254] Duckhee Lee v Soonwoo Kwon [221] | 1-6,0-6 | |
| Challenger Yokohama | 02/28 03:25 | 26 | [138] Tatsuma Ito v Duckhee Lee [254] | 3-6,6-4,6-7 | |
| Challenger Yokohama | 02/27 01:00 | 25 | [254] Duckhee Lee v Enzo Couacaud [246] | 6-0,6-2 | |
| Challenger Yokohama | 02/26 01:00 | 24 | [254] Duckhee Lee v Xia, Zihao [354] | 6-0,6-3 | |
| Bangkok II, Thailand | 02/19 07:35 | 25 | [221] Davidovich Fokina, Alejandro v Duckhee Lee [259] | 6-4,6-2 | |
| Bangkok II, Thailand | 02/18 06:35 | 24 | Duckhee Lee v Thanapet Chanta | 6-2,7-6 | |
| Bangkok, Thaïlande | 02/12 08:15 | 25 | [239] Duckhee Lee v Troicki, Viktor [221] | 1-6,2-6 | |
| Bangkok, Thaïlande | 02/11 03:00 | 24 | [432] Wishaya Trongcharoenchaikul v Duckhee Lee [243] | 3-6,3-6 | |
| Challenger - Chennai | 02/07 05:00 | 26 | [243] Duckhee Lee v Nicola Kuhn [237] | 4-6,4-6 | |
| Challenger - Chennai | 02/05 05:50 | 25 | [243] Duckhee Lee v Sumit Nagal [351] | 6-3,6-4 | |
| Open d'Australie | 01/08 02:55 | 44 | [158] Gregoire Barrere v Duckhee Lee [236] | 6-3,6-2 |