ITF Giappone F2 03/18 01:30 27 Yunseong Chung v Gengo Kikuchi 2-6,6-4,6-1
ITF Giappone F2 03/16 02:45 26 Yunseong Chung v Hiroka Kondo 6-1,7-5
ITF Giappone F2 03/15 02:25 25 Takuto Niki v Yunseong Chung 3-6,6-3,3-6
ITF Giappone F2 03/13 01:00 54 Yunseong Chung v Tung-Lin Wu 7-6,6-2
ITF Turchia F7 02/19 09:35 27 Yunseong Chung v Tallon Griekspoor 6-3,5-7,1-6
ITF Turchia F7 02/18 08:00 26 Pedja Krstin v Yunseong Chung 3-6,6-3,3-6
ITF Turchia F7 02/17 09:30 25 Yunseong Chung v Muhammet Haylaz 6-4,6-4
ITF Turchia F7 02/15 12:00 62 Yunseong Chung v Pavel Krainik 7-5,6-3
ITF Turchia F6 02/09 08:00 25 Yunseong Chung v Lenny Hampel 4-6,1-6
ITF Italia F11 05/25 11:10 - Jacopo Stefanini v Yunseong Chung 6-3,6-4
ITF Italia F11 - Qual. 05/24 08:30 - Yunseong Chung v Alessio Giannuzzi 6-2,6-2
ITF Italia F11 - Qual. 05/23 12:00 - Yunseong Chung v Uladzislau Zhuk 6-2,6-1
ITF Cina F2 - Qual. 04/17 02:00 - Yunseong Chung v Cheong-Eui Kim 7-5,6-7,4-6
ITF Cina F2 - Qual. 04/16 02:00 - Boy Westerhof v Yunseong Chung Walkover
ITF Cina F2 - Qual. 04/14 02:00 - Xin Gao v Yunseong Chung 6-3,4-6,3-6
ITF Cina F2 04/09 02:00 - Yunseong Chung v Tsung-Hua Yang 3-6,2-6
ITF Cina F2 04/07 05:00 - Xin Gao v Yunseong Chung 6-4,3-6,1-6
ITF Giappone F2 03/16 02:25 - Yunseong Chung v Kento Takeuchi 7-6,4-6,1-6
ITF Giappone F1 03/12 02:45 - Yunseong Chung v Gengo Kikuchi 6-1,6-7,5-7
ITF Giappone F1 03/11 06:20 - Takashi Saito v Yunseong Chung 5-7,4-6
ITF Hong Kong F2 07/14 07:25 - Evan Song v Yunseong Chung 7-6,4-6,6-1
ITF Hong Kong F2 - Qual. 07/13 02:00 - Yunseong Chung v Marc Dijkhuizen 6-2,6-1
ITF Corea F1 04/24 01:30 - Yunseong Chung v Maximilian Neuchrist 4-6,2-6
ITF Corea F1 04/22 01:00 - Yunseong Chung v Min-Kyu Song 6-3,5-7,7-5

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.