[2] Hüsler made his ATP main-draw doubles debut at the Swiss Indoors tournament, where he partnered former world No 1.

[4] 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.

[5] Hüsler received a wildcard into the doubles draw for the Swiss Indoors for the second consecutive year, this time with Verbeek as his partner.

[6] The pair upset Michael Venus and Raven Klaasen, the top seeds for the tournament and world No.

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 June, at the 2022 Halle Open he qualified for his first ATP 500 tournament but lost to Mackenzie McDonald.

[11][12] At the Swedish Open, he defeated seventh seed Holger Rune in the first round before losing to Laslo Djere.

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.

[13] Next, he reached the semifinals for the second time ever in his career defeating thirteenth seed Jack Draper in straight sets.

At the 2022 Sofia Open, he reached his first ATP final with a win over fourth seed Lorenzo Musetti.

[19] With Jil Teichmann, they defeated Zhibek Kulambayeva and Alexander Bublik to sweep Kazakhstan 5–0.

At the Adelaide International 2, he beat the previous year finalist, Arthur Rinderknech, in the first round.

Representing Switzerland in the Davis Cup tie against Germany, he won his first match over Oscar Otte.

[27] Switzerland ended up winning the tie over Germany 3–2 to advance to the Davis Cup Finals.

[28] At the Open Sud de France, he was beaten in the second round by top seed and world No.

[33] Seeded sixth at the Arizona Classic, he lost in the second round to qualifier and eventual finalist, Alexander Shevchenko.

[37] Seeded eighth at the BMW Open in Munich, he lost in the second round to Dominic Thiem.

He was defeated in the first round by Wu Yibing in three sets, despite having match point in the third-set tiebreaker.

He marked his debut at this tournament by upsetting eighth seed Maxime Cressy in the first round.

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.

16 Hubert Hurkacz[46] and subsequently dropped out of the top 150 in October 2023, after a string of first round losses, more than a 100 positions down from his career high in February 2023.

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.

Hüsler won in straight sets over Roman Khassanov, salvaging the only point for Switzerland in the tie.