Challenger Yokohama Qual 02/24 05:05 45 Masato Shiga v Yunseong Chung 0-6,5-7
ITF Spain F4 02/08 11:00 26 Ivan Gakhov v Yunseong Chung 6-4,6-4
ITF Spain F4 02/07 11:00 25 Yunseong Chung v Jurgen Briand Retired
ITF Spain F3 01/30 13:40 25 Daniel Gimeno-Traver v Yunseong Chung 6-4,6-1
ITF Spain F2 01/27 10:00 28 Yunseong Chung v Daniel M. D L Nava 3-6,4-6
ITF Spain F2 01/26 13:00 27 Joao Monteiro v Yunseong Chung 7-6,5-7,3-6
ITF Spain F2 01/25 09:00 26 Yunseong Chung v Evgeny Tyurnev 6-4,2-6,6-3
ITF Spain F2 01/23 10:35 25 Yunseong Chung v Nico Mertens 6-4,6-3
ITF Spain F1 01/20 11:50 28 Daniel Munoz-De La Nava v Yunseong Chung 6-4,6-3
ITF Spain F1 01/19 10:00 27 Germain Gigounon v Yunseong Chung 5-7,3-6
ITF Spain F1 01/17 09:00 26 Mikhail Korovin v Yunseong Chung 5-7,1-6
ITF Spain F1 01/15 10:30 25 Yunseong Chung v Pascal Meis 6-0,6-2
ITF Thailand F11 12/05 08:00 25 Wishaya Trongcharoenchaikul v Yunseong Chung 3-6,7-5,7-6
ITF Thailand F11 12/05 04:30 - Wishaya Trong'kul v Yunseong Chung 3-6,7-5,7-6
ITF Thailand F10 11/29 03:00 26 Martins Podzus v Yunseong Chung 6-2,6-3
ITF Thailand F10 11/28 03:00 25 Pruchya Isaro v Yunseong Chung 7-5,5-7,2-6
Challenger Hua Hin Qual 11/19 04:00 46 Pol Wattanakul v Yunseong Chung 7-5,6-4
Challenger Hua Hin Qual 11/18 06:30 45 Kittirat Kerdlaphee v Yunseong Chung 1-6,2-6
Challenger Kobe Qual 11/04 02:00 45 Yunseong Chung v James Trotter 6-7,6-3,5-7
Challenger Shenzhen 2 Qual 10/28 07:35 46 Tsung-Hua Yang v Yunseong Chung 6-3,6-2
Challenger Ningbo 10/20 02:00 26 Yunseong Chung v Jurij Rodionov Walkover
Challenger Ningbo 10/17 04:20 25 Nicolas Jarry v Yunseong Chung 6-7,3-6
Challenger Ningbo Qual 10/16 03:15 54 Yunseong Chung v Vishnu Vardhan 7-6,6-2
Challenger Ningbo Qual 10/15 07:50 46 Shuichi Sekiguchi v Yunseong Chung 4-6,3-6
Challenger Ningbo Qual 10/14 06:10 45 Ruikai Wang v Yunseong Chung 2-6,2-6
ITF Thailand F8 10/12 03:00 27 Yunseong Chung v Sam Barry 2-6,4-6
ITF Thailand F8 10/11 04:55 26 Tung-Lin Wu v Yunseong Chung 5-7,2-6
ITF Thailand F8 10/10 05:00 25 Yunseong Chung v Jirat Navasirisomboon 6-1,6-2
Challenger Kaohsiung 10/04 09:40 25 Tsung-Hua Yang v Yunseong Chung 6-3,6-2
Challenger Gwangju Qual 09/17 01:30 46 Tsung-Hua Yang v Yunseong Chung 7-6,7-5

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.