Tseng Chun-hsin

Tseng Chun-hsin (Chinese: 曾俊欣; pinyin: Zēng Jùnxīn; born 8 August 2001), also known as Jason Tseng, is a Taiwanese professional tennis player. He has a career-high singles ranking of world No. 83 by the ATP, achieved on 8 August 2022. Tseng is currently the No. 1 Taiwanese player. He was also the ITF junior No. 1, reaching the ranking after winning the 2018 French Open boys' singles. He is also part of the Chinese Taipei Davis Cup team since 2018, with a win-loss record of 1–0.

Tseng began playing tennis at the age of five with his father, who worked at a night market in Taiwan. He first trained in an elementary school team located in Yonghe District, New Taipei City.

He is nicknamed "the Night Market Champion" (Chinese: 夜市球王) by the Taiwanese media as his parents used to sell tanghulu at the Lehua Night Market in New Taipei City in order to support his tennis career.

He continued his training at the Mouratoglou Tennis Academy in France from age 13 to 17. During that period, he won singles title at the Petits As in 2015.

In 2018, He won his first ITF Futures event in Vietnam. He won the boys' singles title at the French Open and claimed the Wimbledon boys' singles title in the following month.

He made his ATP debut at the 2019 Miami Open as a wildcard.

In the 2019 Summer Universiade, Tseng won the gold medal in men's singles.

In December 2021, Tseng won his first ATP Challenger title in Maia, Portugal. He made his debut in the top 200 at world No. 188 on 20 December 2021.

He made his Grand Slam debut at the 2022 Australian Open where he received a wildcard.

The following month in February 2022, Tseng won his second ATP Challenger title in Bangalore, India. In April 2022, Tseng won his third ATP Challenger title in Murcia, Spain. He reached a career-high ranking of world No. 110 on 16 May 2022.

He qualified for his second Grand Slam tournament at the 2022 French Open to make his debut at this major. He lost in the first round in five sets in a match that lasted 4 hours 23 minutes against João Sousa. As a result of reaching the semifinals in Bratislava, Tseng made his debut in the top 100, at No. 97 on 13 June 2022.

He participated in the 2022 Next Generation ATP Finals as the sixth seed.

Ranked No. 380, he made his debut in qualifying at the Masters 1000, the 2023 Rolex Shanghai Masters. He qualified for the main draw and defeated Alexander Shevchenko on his debut at this tournament, recording his first Masters win. As a result, he moved close to 80 positions back up, one position shy of the top 300 on 16 October 2023.

In March 2024, he won his fourth Challenger at the Kiskút Open in Szekesfehevar, Hungary and returned to the top 250 on 18 March 2024.

Following his fifth Challenger title at the 2024 Internazionali di Tennis Città di Vicenza in June, and a final showing at the 2024 UniCredit Czech Open in Prostejov, he moved again 80 positions back up and returned to the top 175 on 10 June 2024.

Ranked No. 159, he entered the second round of the main draw at the 2024 Croatia Open as a lucky loser replacing third seed Holger Rune and defeated Fabio Fognini to reach his first ATP Tour quarterfinal. Three weeks later he reached the final at the 2024 San Marino Open, losing to Alexandre Müller in a deciding set tiebreak. As a result, two weeks later, he returned to the top 115 on 19 August 2024.

Following a second ATP career quarterfinal showing at the ATP 500 2025 Rio Open where he qualified and defeated third seed Alejandro Tabilo, his biggest and first top-50 win, and local wildcard and favorite Thiago Monteiro, Tseng returned to the top 100 in the rankings on 24 February 2025. Tseng was only the second player representing Chinese Taipei to reach an ATP 500 quarterfinal, alongside Lu Yen-hsun.

• Chun-Hsin Tseng at the Association of Tennis Professionals
• Chun Hsin Tseng at the International Tennis Federation
• Chun Hsin Tseng at the Davis Cup (archived former page)
• Tseng Chun-Hsin at Olympedia