후에슬러, 마르크-안드레아

2017: ATP debut and first ATP win in doubles

Hüsler made his ATP main-draw doubles debut at the Swiss Indoors tournament, where he partnered former world No 1. Nenad Zimonjić, having received a wildcard into the tournament. The pair defeated Adrian Mannarino and Benoît Paire to give Hüsler a win in his first tour-level match, before losing in the quarterfinals to Marcus Daniell and Dominic Inglot.

2018: First Challenger doubles title, ATP singles debut, and first win

Hüsler claimed his first ATP Challenger Tour doubles title in his first final, partnering Sem Verbeek at the Winnipeg Challenger.

Just over a week later, Hüsler made his ATP Tour singles main-draw debut at the Swiss Open Gstaad, where he recorded his first ATP win defeating former top-10 player Nicolás Almagro in a third-set tiebreaker in the first round, before losing to Facundo Bagnis in the second round. Hüsler received a wildcard into the doubles draw for the Swiss Indoors for the second consecutive year, this time with Verbeek as his partner. The pair upset Michael Venus and Raven Klaasen, the top seeds for the tournament and world No. 7 doubles partnership in the 2018 Doubles Team Race Rankings in the first round.

2019: First Challenger singles title & top 300 debut

On April 21, 2019, Hüsler won his first Challenger title at the 2019 San Luis Open Challenger Tour by beating Adrian Menendez-Maceiras 7–5, 7–6 in the final. As a result, he moved 70 positions up into the top 300 on 22 April at world No. 281 in singles.

2020: Two Challenger titles, ATP semifinals & top 150 debut

Hüsler reached the semifinals of the Austrian Open Kitzbühel, where he beat world No. 12 Fabio Fognini in the second round. As a result, he reached the top 150 at world No. 149 on 9 November 2020.

2021: Maiden ATP doubles title

He won his maiden ATP doubles title at the 2021 Swiss Open Gstaad, partnering Dominic Stricker, defeating Polish pair Szymon Walków and Jan Zieliński.

In September, partnering also with Stricker, he reached the final of the 2021 Challenger Biel/Bienne, Switzerland but withdrew. As a result, he reached a month later a new career-high doubles ranking of World No. 132 on 25 October 2021. He also reached the final in singles, where he lost to Liam Broady but climbed to No. 155 on 18 October 2021.

He finished the year ranked No. 188 in singles.

2022: Major & Masters & top 60 debuts, Swiss No. 1, Maiden ATP singles title

Hüsler started his 2022 season at the Traralgon International. Seeded ninth, he lost in the third round to eighth seed Mikhail Kukushkin.

In April, he won two more Challenger titles in Mexico. As a result, he reached a career-high ranking of No. 121 on 9 May 2022.

In June, at the 2022 Halle Open he qualified for his first ATP 500 tournament but lost to Mackenzie McDonald. Hüsler made his Grand Slam debut after qualifying for Wimbledon, where he lost to lucky loser Hugo Grenier, who was also making his debut, in the first round in five sets.

At the Swedish Open, he defeated seventh seed Holger Rune in the first round before losing to Laslo Djere. As a result, he reached the top 100 at world No. 99 on 18 July 2022. He became the Swiss No. 1 player until 8 August 2022.

At the Winston-Salem Open, he reached only his second career quarterfinal as a qualifier after getting a second-round bye after seventh seed Sebastián Báez withdrew, defeating previous year finalist and wildcard Mikael Ymer and defending champion and eleventh seed Ilya Ivashka. Next, he reached the semifinals for the second time ever in his career defeating thirteenth seed Jack Draper in straight sets. He was only the fourth qualifier to reach the tournament semifinals ever. He lost again to Laslo Đere in the semifinal. As a result, he reached a new career-high ranking of No. 85 becoming again the Swiss No. 1 player on 29 August 2022.

At the 2022 Sofia Open, he reached his first ATP final with a win over fourth seed Lorenzo Musetti. He defeated again fifth seed Holger Rune to win his maiden ATP title. As a result, he climbed 31 spots to a new career-high of No. 64 in the rankings on 3 October 2022.

He made his Masters 1000 debut at the 2022 Rolex Paris Masters after defeating Hugo Gaston and Laslo Djere in qualifying. On his debut, he defeated 11th seed Jannik Sinner in his first-round match. He lost to Karen Khachanov in the second round. As a result, he reached a career-high ranking of world No. 58 on 7 November 2022.

2023-2024: United Cup & Top 50 debuts, loss of form, 200 positions ranking drop

Hüsler started his 2023 season by representing Switzerland at the first edition of the United Cup. Switzerland was in Group B alongside Kazakhstan and Poland. Against Kazakhstan, he beat Timofey Skatov. With Jil Teichmann, they defeated Zhibek Kulambayeva and Alexander Bublik to sweep Kazakhstan 5–0. Against Poland, he beat Daniel Michalski. In doubles, he and Belinda Bencic defeated Alicja Rosolska and Kacper Żuk. Poland ended up winning the tie over Switzerland 3–2. Switzerland was ultimately eliminated from the United Cup and ended second in Group B. At the Adelaide International 2, he beat the previous year finalist, Arthur Rinderknech, in the first round. He was defeated in the second round by third seed and world No. 20, Karen Khachanov. At the Australian Open, he lost in a five-set battle in the first round to Australian wildcard John Millman. He reached the top 50 at world No. 49 following the Australian Open on 6 February 2023.

Representing Switzerland in the Davis Cup tie against Germany, he won his first match over Oscar Otte. In his second match, he beat world No. 14 Alexander Zverev. Switzerland ended up winning the tie over Germany 3–2 to advance to the Davis Cup Finals. At the Open Sud de France, he was beaten in the second round by top seed and world No. 9, Holger Rune. In Rotterdam, he lost in the first round to Dutch wildcard Gijs Brouwer. Seeded eighth at the Open 13 Provence, he was defeated in the first round by Grégoire Barrère. In Dubai, he lost in the first round to Lorenzo Sonego.

In March, Hüsler made his debut at the BNP Paribas Open. He was eliminated from the tournament in the first round by Pedro Martínez. Seeded sixth at the Arizona Classic, he lost in the second round to qualifier and eventual finalist, Alexander Shevchenko. In Miami, also on his debut, he won his first round match over Albert Ramos Viñolas before losing in the second round to 16th seed and world No. 19, Tommy Paul.

Hüsler started his clay-court season at the Mexico City Open. As the top seed and the defending champion, he lost in the second round to qualifier Federico Gaio. At the Monte-Carlo Masters, he was defeated in the first round by Jaume Munar. Seeded eighth at the BMW Open in Munich, he lost in the second round to Dominic Thiem. In Madrid, he fell in his first-round match to Cristian Garín. At the Italian Open, he lost in the first round to Jason Kubler in three sets, despite having a 7–6(6), 3–0 lead in the match. Hüsler played his final tournament before Roland Garros at the Geneva Open. He was defeated in the first round by Wu Yibing in three sets, despite having match point in the third-set tiebreaker. At the French Open, he lost in the first round to Daniel Altmaier in straight sets.

Hüsler started his grass-court season at the Libéma Open in 's-Hertogenbosch. He marked his debut at this tournament by upsetting eighth seed Maxime Cressy in the first round. This was his first tour-level win on grass. He lost in five sets at the 2023 Wimbledon Championships to world No. 116, lucky loser and Wimbledon debutant Yosuke Watanuki, after being two sets to love up, in a close to a four hours match that was suspended due to darkness.

He suffered another tough first round five sets loss also from two sets to love up at the US Open, to world No. 16 Hubert Hurkacz and subsequently dropped out of the top 150 in October, after a string of first round losses, more than a 100 positions down from his career high in February. Ranked No. 200, at the 2023 Sofia Open, where he was the defending champion, he qualified for the main draw.

He further dropped close to 200 positions from his singles career-high on 1 April 2024 to world No. 237 in the rankings. In mid-April, he qualified for the main draw of the 2024 BMW Open in Munich and defeated two Germans, wildcard Marko Topo and Yannick Hanfmann to reach his first quarterfinal in more than a year.