ITF Chinese Taipei F3 10/26 04:00 25 He, Ting-Hou v Yunseong Chung 2-6,4-6
ITF Chinese Taipei F2 10/21 02:00 27 Yunseong Chung v Kuan-Yi Lee 0-6,2-6
ITF Chinese Taipei F2 10/20 02:00 26 Yunseong Chung v Yu, Cheng-Yu 7-6,6-3
ITF Chinese Taipei F2 10/19 02:00 25 Yunseong Chung v Tsai, Ching-Huang 6-4,6-2
Challenger Ho Chi Minh City Qual 10/10 04:45 54 Sekiguchi, Shuichi v Yunseong Chung 6-4,4-6,6-4
Challenger Ho Chi Minh City Qual 10/09 10:05 46 Yunseong Chung v Cacic, Nikola 7-6,7-6
Challenger Ho Chi Minh City Qual 10/08 07:20 45 Yunseong Chung v Nguyen, Dac Tien 6-0,6-3
ITF Vietnam F4 09/13 04:35 25 Yunseong Chung v Ito, Yuichi 4-6,7-5,4-6
ITF Thailand F3 09/08 02:00 27 Renta Tokuda v Yunseong Chung 6-3,7-6
ITF Thailand F3 09/07 02:00 26 Yunseong Chung v Navasirisomboon, Jirat 6-0,6-4
ITF Thailand F3 09/05 03:00 25 Yunseong Chung v Wattanakul, Pol 6-3,2-6,6-3
ITF Thailand F2 08/31 06:05 26 Yunseong Chung v Kuan-Yi Lee 3-6,3-6
ITF Thailand F2 08/29 03:00 25 Wattanakul, Pol v Yunseong Chung 3-6,4-6
ITF Thailand F4 08/26 03:00 28 Yunseong Chung v Fajing Sun 4-6,3-6
ITF Thailand F4 08/25 03:00 27 Yunseong Chung v Antoine Escoffier 6-4,6-3
ITF Thailand F4 08/24 04:35 26 Kuan-Yi Lee v Yunseong Chung 3-6,5-7
ITF Thailand F4 08/23 05:00 25 Yunseong Chung v Brackenreg, Cody 6-2,6-1
ITF Vietnam F8 08/09 06:30 25 Nam Hoang Ly v Yunseong Chung 6-3,7-5
ITF Vietnam F8 08/03 03:00 25 Yunseong Chung v Yusuke Takahashi 2-6,6-4,1-6
ITF Korea F1 06/16 02:35 26 Yunseong Chung v Seol, Jae-Min 4-6,6-4,4-6
ITF Korea F1 06/15 04:50 25 Yunseong Chung v Jeamoon Lee 6-1,6-3
ITF China F7 05/22 03:00 29 Yunseong Chung v Akira Santillan 1-6,4-6
ITF China F7 05/21 03:00 28 Soonwoo Kwon v Yunseong Chung 4-6,2-6
ITF China F7 05/20 07:35 27 Tearney, Finn v Yunseong Chung 6-0,4-6,5-7
ITF China F7 05/19 03:30 26 Yunseong Chung v Cai, Zhao 6-3,6-2
ITF China F7 05/18 02:00 25 Ouyang, Bowen v Yunseong Chung 6-4,2-6,1-6
ITF Japan F4 03/30 01:00 25 Yunseong Chung v Tearney, Finn 6-3,4-6,1-6
ITF Japan F3 03/23 04:15 26 Yunseong Chung v Gao, Xin 4-6,0-6
ITF Japan F3 03/22 04:10 25 Yunseong Chung v Ouyang, Bowen 6-3,6-4
ITF Japan F2 03/19 02:00 28 Yunseong Chung v Kibi, Yuya 6-1,1-6,4-6

Wikipedia - Chung Yun-seong

Chung Yun-seong (Korean: 정윤성; born 27 March 1998) is a South Korean tennis player.

Chung has a career high ATP singles ranking of No. 233 achieved on 22 July 2019. He also has a career high ATP doubles ranking of No. 129 achieved on 22 May 2023. Chung has won three doubles ATP Challenger titles as well as four ITF singles and five doubles titles.

On the junior tour, Chung had a career-high combined ranking of 3 achieved on 21 March 2016. Chung was a semifinalist at the 2016 Australian Open boys' singles event and the 2015 US Open boys' singles event where he fell to both eventual champions Oliver Anderson and Taylor Fritz, respectively. Chung was also a singles finalist at the Osaka Mayor's Cup in 2014.

He and Orlando Luz lost to Yishai Oliel of Israel and Patrik Rikl of the Czech Republic in the final of the 2016 French Open boys' doubles, 6–3, 6–4.