Gauthier Onclin

In January, Onclin reached the semifinals of the 2023 BW Open in Ottignies-Louvain-la-Neuve where he lost to eventual champion and compatriot David Goffin.

In May, he defeated the higher-ranked Elias Ymer at a Challenger event in Bordeaux in the first round. At the 2023 French Open he defeated Nicholas David Ionel in straight sets in the first round of qualifying before losing to Argentine Thiago Agustin Tirante in three sets. Onclin got his revenge over the Argentine in the qualifying at the 2023 Wimbledon Championships, winning in straight sets during his first ever grass-court summer, as his junior years coincided with the grass-court portion of the Tour cancellation due to the COVID-19 pandemic.

In October, he received a wildcard in doubles for the European Open in Antwerp, alongside compatriot Michael Geerts. At the same tournament, in the qualifying singles competition, he defeated higher-ranked American Maxime Cressy.

In May, Onclin reached his first Challenger final at the Prague Open. He lost to the former world No. 35 Jiří Veselý. In October and November 2024 he reached two M25 finals in Portugal where he faced the same opponent, losing the first to Frederico Ferreira Silva but winning the second at the Vale do Lobo Open III. He closed out 2024 with a second title in two weeks, and 12th ITF title, winning the M25 in Monastir, Tunisia, recording 10 consecutive victories on the ITF circuit.

He started the season by increasing his 2024 winning streak to 13 matches after he made it through the qualifications at the 2025 Australian Open into the main draw for his Grand Slam debut, defeating Roman Andres Burruchaga and Americans Aleksandar Kovacevic and Mackenzie McDonald.