# 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.

## Junior Grand Slam finals
### Doubles: 1 (1 runner-up)

| Outcome | Year | Championship | Surface | Partner | Opponent | Score |
| Runner-up | 2016 | French Open | Clay | Orlando Luz | Yishai Oliel Patrik Rikl | 3–6, 4–6 |

## ATP Challenger and ITF Futures/World Tennis Tour finals
### Singles: 8 (4–4)

* Legend
* ATP Challenger (0–0)
* ITF Futures (4–4)
* Finals by surface
* Hard (4–4)
* Clay (0–0)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Loss | 0–1 | Jun 2014 | Korea F6, Gimcheon | Futures | Hard | Kim Cheong-Eui | 2–6, 4–6 |
| Loss | 0–2 | Aug 2015 | Korea F3, Gimcheon | Futures | Hard | Jung-Woong Na | 3–6, 1–6 |
| Loss | 0–3 | May 2016 | China F7, Wuhan | Futures | Hard | Akira Santillan | 1–6, 4–6 |
| Win | 1–3 | Jun 2018 | Korea F2, Gyeongsan | Futures | Hard | Nam Ji-sung | 6–4, 6–3 |
| Win | 2–3 | Jun 2018 | Korea F3, Daegu | Futures | Hard | Nam Ji-sung | 6–1, 6–3 |
| Win | 3–3 | May 2021 | M15 Monastir, Tunisia | World Tennis Tour | Hard | Aziz Dougaz | 6–1, 7–5 |
| Win | 4–3 | May 2021 | M15 Monastir, Tunisia | World Tennis Tour | Hard | Jeremy Beale | 6–4, 6–2 |
| Loss | 4–4 | Jan 2022 | M25 Monastir, Tunisia | World Tennis Tour | Hard | Harold Mayot | 4–6, 6–0, 4–6 |

### Doubles: 25 (14 titles, 11 runner-ups)

* Legend
* ATP Challenger (3–5)
* ITF Futures (11–6)
* Finals by surface
* Hard (13–9)
* Clay (1–2)
| Result | W–L | Date | Tournament | Tier | Surface | Partner | Opponents | Score |
| Loss | 0–1 | Aug 2015 | Astana, Kazakhstan | Challenger | Hard | Jurabek Karimov | Konstantin Kravchuk Denys Molchanov | 2–6, 2–6 |
| Win | 1–1 | Mar 2016 | Japan F2, Tokyo | Futures | Hard | Soonwoo Kwon | Issei Okamura Kento Takeuchi | 2–6, 6–2, [10–3] |
| Loss | 1–2 | Jun 2016 | Korea F2, Sangju | Futures | Hard | Lim Yong-kyu | Nam Ji-sung Song Min-kyu | 4–6, 4–6 |
| Loss | 1–3 | Aug 2016 | Thailand F1, Hua Hin | Futures | Hard | Xin Gao | Chen Ti John Paul Fruttero | 2–6, 2–6 |
| Win | 2–3 | Oct 2016 | Chinese Taipei F2, Kaohsiung | Futures | Hard | Patrik Niklas-Salminen | Yu Hsiang Chiu Shao-Fan Liu | 7–5, 6–4 |
| Win | 3–3 | Dec 2016 | Indonesia F4, Jakarta | Futures | Hard | Shintaro Imai | Julien Cagnina Enzo Couacaud | 6–2, 6–4 |
| Win | 4–3 | Dec 2016 | Indonesia F5, Jakarta | Futures | Hard | Shintaro Imai | Issei Okamura Kento Takeuchi | 6–2, 3–6, [10–6] |
| Win | 5–3 | Feb 2018 | Spain F3, Mallorca | Futures | Clay | Rio Noguchi | Bruno Sant'Anna David Vega Hernández | 2–6, 7–6$^{(8–6)}$, [10–8] |
| Win | 6–3 | Jun 2018 | Korea F3, Daegu | Futures | Hard | Seong Chan Hong | Soonwoo Kwon Lim Yong-kyu | walkover |
| Loss | 6–4 | Jul 2019 | Astana, Kazakhstan | Challenger | Hard | Nam Ji-sung | Andrey Golubev Aleksandr Nedovyesov | 4–6, 4–6 |
| Loss | 6–5 | Feb 2020 | M25 Nonthaburi, Thailand | World Tennis Tour | Hard | Corentin Denolly | Sonchat Ratiwatana Sanchai Ratiwatana | 6–3, 4–6, [5–10] |
| Win | 7–5 | Feb 2020 | M25 Aktobe, Kazakhstan | World Tennis Tour | Hard | Aldin Šetkić | Riccardo Balzerani Francesco Forti | 6–3, 6–4 |
| Loss | 7–6 | Feb 2021 | M15 Antalya, Turkey | World Tennis Tour | Clay | Oleksandr Ovcharenko | Max Houkes Sidane Pontjodikromo | 5–7, 1–6 |
| Win | 8–6 | May 2021 | M15 Monastir, Tunisia | World Tennis Tour | Hard | Shintaro Imai | Filip Bergevi Jonathan Mridha | 6–2, 7–6$^{(7–4)}$ |
| Win | 9–6 | May 2021 | M15 Monastir, Tunisia | World Tennis Tour | Hard | Shintaro Imai | Aziz Dougaz Benjamin Lock | 6–3, 6–2 |
| Loss | 9–7 | Jul 2021 | M25 Champaign, United States | World Tennis Tour | Hard | Rio Noguchi | Ben Shelton Eliot Spizzirri | 4–6, 0–6 |
| Win | 10–7 | Jun 2022 | Orlando, USA | Challenger | Hard | Michail Pervolarakis | Malek Jaziri Kaichi Uchida | 6–7$^{(5–7)}$, 7–6$^{(7–3)}$, [16–14] |
| Win | 11–7 | Sep 2022 | Nonthaburi, Thailand | Challenger | Hard | Ajeet Rai | Francis Casey Alcantara Christopher Rungkat | 6–1, 7–6$^{(8–6)}$ |
| Loss | 11–8 | Oct 2022 | Seoul, South Korea | Challenger | Hard | Aleksandar Kovacevic | Kaichi Uchida Wu Tung-lin | 7–6$^{(7–2)}$, 5–7, [9–11] |
| Loss | 11–9 | Jan 2023 | Tigre, Argentina | Challenger | Clay | Christian Langmo | Daniel Dutra da Silva Oleg Prihodko | 2–6, 2–6 |
| Win | 12–9 | Feb 2023 | Bangalore, India | Challenger | Hard | Hsu Yu-hsiou | Anirudh Chandrasekar Vijay Sundar Prashanth | 3–6, 7–6$^{(9–7)}$, [11–9] |
| Loss | 12–10 | Apr 2023 | M25 Kashiwa, Japan | World Tennis Tour | Hard | Shintaro Imai | Hsu Yu-hsiou Huang Tsung-hao | 6–7$^{(5–7)}$, 6–2, [10–12] |
| Win | 13–10 | Apr 2023 | M25 Jakarta, Indonesia | World Tennis Tour | Hard | Jeong Yeong-Seok | Makoto Ochi Yuta Shimizu | 4–6, 7–6$^{(7–1)}$, [10–8] |
| Loss | 13–11 | Apr 2023 | Seoul, South Korea | Challenger | Hard | Yuta Shimizu | Max Purcell Yasutaka Uchiyama | 1–6, 4–6 |
| Win | 14–11 | Jun 2023 | M25 Anseong, South Korea | World Tennis Tour | Hard | Takeru Yuzuki | Shunsuke Mitsui Naoki Tajima | 7–6$^{(7–3)}$, 6–4 |