An Jae-sung
An Jae-sung is a retired South Korean tennis player.
An has a career high ATP singles ranking of 289 achieved on 14 April 2008. He also has a career high doubles ranking of 454 achieved on 18 August 2008.
Early life and career
An attended Konkuk University. While a student, he represented South Korea in tennis at the 2006 Asian Games in Doha, Qatar, where he and his teammates won a gold medal in the men's team event, thus securing an exemption from his mandatory military service.An has been a member of the South Korea Davis Cup team from 2005 until 2008, competing in the World Group first round tie in 2008 against Germany.
In 2008, he captured his only ATP Challenger Tour doubles title in Moncton, Canada.
He retired in 2014, and now runs a tennis academy in Jeju.
ATP Challenger and ITF Futures finals
Singles: 11 (3–8)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Loss | 0–1 | Karuizawa, Japan | Futures | Clay |  Kwon Oh-hee | 2–6, 5–7 | |
| Loss | 0–2 | Kōfu, Japan | Futures | Carpet | Kwon Hyung-tae | 5–7, 1–6 | |
| Win | 1–2 | Seogwipo, South Korea | Futures | Hard |  Norikazu Sugiyama | 3–6, 6–3, 6–2 | |
| Win | 2–2 | Khon Kaen, Thailand | Futures | Hard |  Simon Rea | 6–4, 6–1 | |
| Loss | 2–3 | Chiang Mai, Thailand | Futures | Hard |  Justin Diao Natale | 4–6, 4–6 | |
| Loss | 0–1 | New Delhi, India | Challenger | Hard |  Aisam-ul-Haq Qureshi | 5–7, 4–6 | |
| Loss | 2–4 | Nishitōkyō, Japan | Futures | Hard | Gouichi Motomura | 7–5, 1–6, 2–6 | |
| Win | 3–4 | Kōfu, Japan | Futures | Hard | Yūichi Sugita | 5–7, 6–4, 7–6 | |
| Loss | 3–5 | Tarakan, Indonesia | Futures | Hard |  Christopher Rungkat | 3–6, 6–0, 2–6 | |
| Loss | 3–6 | Shenzhen, China | Futures | Hard |  Zhang Ze | 4–6, 2–6 | |
| Loss | 3–7 | Taipei, Taiwan | Futures | Hard | Hiroki Moriya | 3–6, 6–4, 3–6 |
Doubles: 17 (9–8)
| Result | W–L | Date | Tournament | Tier | Surface | Partner | Opponents | Score |
| Loss | 0–1 | Seogwipo, South Korea | Futures | Hard | Im Kyu-tae | Kim Dong-hyun Kwon Oh-hee | 6–7, 2–6 | |
| Win | 1–1 | Andong, South Korea | Futures | Hard | Chung Hee-seok | Jun Woong-sun Kim Sun-yong | 7–5, 6–4 | |
| Win | 2–1 | Andong, South Korea | Futures | Hard | Kwon Hyung-tae | Im Kyu-tae Takahiro Terachi | 3–6, 4–6 | |
| Loss | 2–2 | Kusatsu, Japan | Futures | Carpet | Kim Dong-hyun | Yaoki Ishii Joji Miyao | 6–3, 4–6, 2–6 | |
| Loss | 2–3 | Bangkok, Thailand | Futures | Hard | Chung Hee-seok | Yu Xinyuan Zeng Shaoxuan | 2–6, 7–5, 4–6 | |
| Loss | 2–4 | Nonthaburi, Thailand | Futures | Hard | Chung Hee-seok | Yu Xinyuan Zeng Shaoxuan | 2–6, 6–4, 2–6 | |
| Loss | 2–5 | Kōfu, Japan | Futures | Carpet | Daniel Yoo | Akito Higa Tomohiro Shinokawa | 6–3, 4–6, 4–6 | |
| Loss | 2–6 | Gimcheon, South Korea | Futures | Hard | Chung Hee-seok |  Óscar Burrieza Nikolai Nesterov | 6–1, 7–5 | |
| Win | 1–0 | Moncton, Canada | Challenger | Hard | Hiroki Kondo |  Daniel Chu Adil Shamasdin | 6–2, 2–6, | |
| Win | 3–6 | Seogwipo, South Korea | Futures | Hard | Lee Chul-hee |  Gary Lugassy Ludovic Walter | 7–6, 7–5 | |
| Win | 4–6 | Gimcheon, South Korea | Futures | Hard | Lim Yong-kyu | Junn Mitsuhashi Yi Chu-huan | 7–6, 6–4 | |
| Win | 5–6 | Bandung, Indonesia | Futures | Hard | Kim Young-jun | Elbert Sie Karunuday Singh | 6–2, 5–7, | |
| Win | 6–6 | Daegu, South Korea | Futures | Hard | Kim Young-jun |  Jaan-Frederik Brunken Michael McClune | 5–7, 7–5, | |
| Loss | 6–7 | Cairns, Australia | Futures | Hard | Elbert Sie |  Brydan Klein James Lemke | w/o | |
| Loss | 6–8 | Kaohsiung, Taiwan | Futures | Hard | Kim Young-jun | Denis Matsukevich Frederik Nielsen | 4–6, 1–6 | |
| Win | 7–8 | Ōarai, Japan | Futures | Hard | Arata Onozawa | Toshihide Matsui Yi Chu-huan | 2–6, 6–1, | |
| Win | 8–8 | Seoul, South Korea | Futures | Hard | Lim Yong-kyu | Chung Hyeon Nam Ji-sung | 6–3, 6–2 |