Yannick Hanfmann

Hanfmann made his ATP main-draw debut at the 2017 BMW Open after defeating Arthur De Greef and Uladzimir Ignatik in the qualifying rounds. Ranked world No. 273, he upset both Gerald Melzer and Thomaz Bellucci to reach the quarterfinals, where he lost to second seed Roberto Bautista Agut.

At the 2017 Swiss Open Gstaad, Hanfmann made a sensational run to the final after defeating Facundo Bagnis, third seed and defending champion Feliciano López, eighth seed João Sousa and sixth seed Robin Haase, again as a qualifier. In his semifinal victory over Haase he saved four match points. He lost to Fabio Fognini in the final.

He reached the top 100 at world No. 99 on 16 July 2018, following his Challenger title in Braunschweig, Germany.

Hanfmann reached his second career ATP Tour final at the 2020 Generali Open Kitzbühel in Austria, but lost in straight sets to Serbian Miomir Kecmanović.

He recorded his maiden top-10 win against Gaël Monfils in the first round of the 2020 Hamburg European Open in Germany.

He made his debut at the 2021 Australian Open and at a Masters 1000 level at the Miami Open where he defeated Steve Johnson.

At the 2022 Australian Open, he won his first match at a Grand Slam event defeating wildcard Thanasi Kokkinakis.

He skipped the clay season in Europe and was unable to qualify for the French Open and Wimbledon and as a result his ranking dropped to No. 152 on 18 July 2022.

Following Wimbledon he reached the round of 16 at the Swiss Open as a qualifier. At Kitzbühel, he reached his fourth ATP semifinal overall and second at this tournament defeating Dominic Thiem for one of the biggest wins in his career.

At the Chile Open, he reached his ninth quarterfinal on clay and of his career as a qualifier defeating two Spaniards, defending champion Pedro Martínez and Roberto Carballés Baena.

At the 2023 U.S. Men's Clay Court Championships, he reached his tenth clay-court quarterfinal as a qualifier defeating Yosuke Watanuki and second seed Tommy Paul, his biggest win in three years. Next he reached his fifth ATP semifinal defeating Tomáš Macháč. He lost to Tomás Martín Etcheverry in straight sets. As a result, he rose close to 25 positions into the top 110, on 10 April 2023.

At the Madrid Open, on his main draw debut as a qualifier, he reached the third round on a Masters level for the first time in his career and in only his second Masters participation, defeating Juan Pablo Varillas and 15th seed Lorenzo Musetti.

Ranked No. 101 at the Italian Open on his debut at the tournament, also as a qualifier, he reached the third round defeating Nicolás Jarry and ninth seed Taylor Fritz for his first top-10 win of the season and only second in his career. Next, he defeated Marco Cecchinato to reach his first Masters fourth round and sixth seed Andrey Rublev, his third career top-10 win, to reach his first Masters quarterfinal. He lost to world No. 3, Daniil Medvedev, in straight sets. As a result, he moved close to 40 positions up to a new career-high singles ranking of world No. 64, on 22 May 2023. As the second qualifying seed, he entered the main draw of the 2023 French Open as a lucky loser and defeated Thiago Monteiro in the first round in five sets for his first win at this major.

At his home tournament, the Halle Open, he reached the second round as a wildcard defeating compatriot Louis Wessels. As a result, he moved into the top 50 in the rankings at world No. 48, on 26 June 2023. At the next grass court tournament, the Mallorca Championships, he reached the semifinals defeating the top seed Stefanos Tsitsipas and retiring wildcard Feliciano López. He lost his semifinal match to Adrian Mannarino. Hanfmann improved his career-high ranking to No. 45 on 3 July 2023.

With his compatriot Dominik Koepfer he reached the semifinals of the 2024 Australian Open as an unseeded pair, in only his second participation in the doubles competition at this Major, and third overall at Grand Slams.