2018–2026: ATP debut, top 100, United Cup finalist Paul made his ATP main draw debut as a wildcard at the
2018 Swiss Open Gstaad in the doubles draw partnering
Adrian Bodmer, defeating fellow Swiss wildcards
Marc-Andrea Hüsler and
Luca Margaroli before losing to top seeds
Robin Haase and
Matwe Middelkoop in the quarterfinals. At the same tournament he also participated in the qualifying competition where he defeated
Matteo Donati. He received a wildcard for the singles qualifying competition at the
2021 Geneva Open but lost to
Pablo Cuevas in three sets. He also entered the
2021 Swiss Open Gstaad as a wildcard in the doubles draw partnering with
Leandro Riedi and the pair won their maiden doubles match as a team against
Evan King and
Max Schnur and then reached the semifinals after a walkover from
Zizou Bergs and
Tallon Griekspoor. Paul also entered the
2022 Geneva Open as a wildcard with Riedi where they reached the quarterfinals defeating second seeds
Jamie Murray and
Bruno Soares. He also received wildcards in doubles for the
2024 Geneva Open partnering
Antoine Bellier and in singles for the qualifying competition. Paul made his debut at the
2026 United Cup as part of team Switzerland and recorded four wins in mixed doubles with
Belinda Bencic, helping the team reach the final of the event for the first time. ==ATP Challenger and ITF Tour finals==