Challenger Nonthaburi 08/30 08:15 25 [418] Yunseong Chung v Billy Harris [305] 3-6,6-4,4-6
Challenger Nonthaburi 08/29 06:10 19 [418] Yunseong Chung v Timo Legout [495] 7-6,6-2
Challenger Nonthaburi - Kval 08/28 07:25 14 [414] Yunseong Chung v Dayne Kelly [490] 6-4,3-6,6-4
Challenger Nonthaburi 08/21 07:00 14 Yunseong Chung v Yuta Shimizu Cancelled
Challenger Santo Domingo 08/15 19:40 19 [289] Nicolas Mejia v Yunseong Chung [423] 6-3,4-6,6-4
Challenger Santo Domingo 08/14 21:00 14 [107] Evan King v Yunseong Chung [414] 2-6,5-7
Challenger - Chicago 08/08 18:00 14 [186] Enzo Couacaud v Yunseong Chung [414] 6-4,6-2
Challenger Lexington 08/01 17:25 25 [403] Yunseong Chung v Roberto Quiroz [267] 2-6,7-5,1-6
Challenger Bogota 07/04 19:05 19 [422] Yunseong Chung v Arklon H D P Cordova [277] 3-6,7-6,6-7
Challenger Bogota 07/03 19:45 14 Yunseong Chung v Gabriel Tumasonis 6-4,2-6,6-2
Challenger Cali 06/30 17:30 27 [422] Yunseong Chung v Facundo Mena [160] 3-6,7-5,6-7
Challenger Cali 06/29 18:00 26 [247] Gerald Melzer v Yunseong Chung [422] 4-6,2-6
Challenger Cali 06/28 17:00 25 [422] Yunseong Chung v Mateus Alves [411] 6-4,6-0
Challenger Cali 06/27 15:00 19 Yunseong Chung v Ignacio Monzon 1-6,7-6,6-2
Challenger Cali 06/26 15:30 14 Yunseong Chung v Miguel Angel Sarria 6-2,6-0
ITF M25 Tulsa 06/23 15:15 26 Stefan Dostanic v Yunseong Chung Retired
ITF M25 Tulsa 06/22 01:10 25 Ezekiel Clark v Yunseong Chung 4-6,3-6
ITF M25 Santo Domingo 06/17 14:00 27 Martin Damm v Yunseong Chung 2-6,6-2,7-6
ITF M25 Santo Domingo 06/16 13:30 26 Arvid Nordquist v Yunseong Chung 6-7,4-6
ITF M25 Santo Domingo 06/15 15:15 25 Alejandro Jose Gandini v Yunseong Chung 2-6,2-6
Challenger Orlando 06/05 20:05 14 Matija Pecotic v Yunseong Chung 0-6,6-3,6-2
Challenger Little Rock 05/30 16:40 19 [357] Adrian Menendez-Maceiras v Yunseong Chung [392] 1-6,6-0,6-4
Challenger Little Rock 05/29 18:05 14 [445] Christian Langmo v Yunseong Chung [392] Retired
Challenger Morelos 04/30 20:00 28 [448] Adrian Menendez-Maceiras v Yunseong Chung [374] 1-6,6-1,6-4
Challenger Morelos 04/29 18:00 27 [374] Yunseong Chung v Keegan Smith [421] 6-1,6-4
Challenger Morelos 04/27 16:25 26 [347] Aleksandar Kovacevic v Yunseong Chung [374] 6-3,5-7,4-6
Challenger Morelos 04/26 00:30 25 [408] Bernard Tomic v Yunseong Chung [374] 3-6,6-3,4-6
Challenger Tallahassee 04/18 16:30 19 [373] Yunseong Chung v Christian Langmo [471] 5-7,5-7
Challenger Tallahassee 04/17 16:50 14 Yunseong Chung v John McNally 6-3,6-4
Challenger Salinas 04/06 17:30 26 [374] Yunseong Chung v JC Aragone [376] 5-7,4-6

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.