Challenger - Nonthaburi | 01/16 07:00 | 25 | [218] Gauthier Onclin v Clement Tabur [233] | 6-4,6-3 | |
Australian Open | 01/10 05:15 | 14 | [103] Aleksandar Kovacevic v Gauthier Onclin [220] | 6-3,6-7,7-6 | |
Challenger - Nonthaburi | 01/04 03:30 | 27 | [231] Gauthier Onclin v Lucas Pouille [329] | 3-6,2-6 | |
Challenger - Nonthaburi | 01/03 03:00 | 26 | [251] Evgeny Donskoy v Gauthier Onclin [231] | 3-6,3-6 | |
Challenger - Nonthaburi | 01/01 08:45 | 25 | [231] Gauthier Onclin v Yasutaka Uchiyama [269] | 7-5,6-2 | |
Challenger Danderyd | 11/16 09:00 | 26 | Gauthier Onclin v Flavio Cobolli | Walkover | |
Challenger Danderyd | 11/14 17:15 | 25 | [380] Leo Borg v Gauthier Onclin [227] | 6-2,4-6,0-6 | |
Challenger - Helsinki | 11/06 13:35 | 19 | [228] Gauthier Onclin v Maximilian Neuchrist [258] | 5-7,4-6 | |
Challenger - Helsinki | 11/05 10:30 | 14 | Gauthier Onclin v Markus Molder | 6-0,6-4 | |
Challenger - Bergamo | 10/31 09:00 | 25 | [216] Gauthier Onclin v Radu Albot [132] | 7-6,0-6,0-6 | |
Challenger - Ortisei | 10/23 15:25 | 25 | [310] Maks Kasnikowski v Gauthier Onclin [216] | 6-1,6-4 | |
ATP - Antwerp | 10/16 09:30 | 19 | [214] Gauthier Onclin v Giovanni M Perricard [226] | 4-6,2-6 | |
ATP - Antwerp | 10/15 11:30 | 14 | [112] Maxime Cressy v Gauthier Onclin [206] | 2-6,6-1,6-7 | |
Challenger - Rennes | 09/13 16:30 | 26 | [195] Gauthier Onclin v Benjamin Bonzi [102] | 1-6,2-6 | |
Challenger - Rennes | 09/11 15:00 | 25 | [195] Gauthier Onclin v Giulio Zeppieri [136] | 6-2,6-2 | |
Challenger - Istanbul | 09/05 10:40 | 25 | [264] Altug Celikbilek v Gauthier Onclin [198] | 6-1,6-0 | |
US Open | 08/25 18:30 | 15 | [205] Gauthier Onclin v Sho Shimabukuro [159] | 4-6,6-7 | |
US Open | 08/23 18:05 | 14 | [205] Gauthier Onclin v Marco Trungelliti [228] | 6-3,6-4 | |
Challenger - Meerbusch | 08/10 15:30 | 26 | [203] Gauthier Onclin v Max Hans Rehberg [413] | 6-7,6-7 | |
Challenger - Meerbusch | 08/08 13:05 | 25 | [203] Gauthier Onclin v Gerard Campana Lee [419] | 2-6,7-5,6-1 | |
Challenger - Luedenscheid | 08/04 12:00 | 27 | [208] Gauthier Onclin v Benoit Paire [126] | 4-6,4-6 | |
Challenger - Luedenscheid | 08/03 14:00 | 26 | [208] Gauthier Onclin v Santiago Rodriguez Taverna [272] | 6-1,6-4 | |
Challenger - Luedenscheid | 08/01 15:40 | 25 | [148] Jan Choinski v Gauthier Onclin [208] | 4-6,2-6 | |
Challenger - Amersfoort | 07/21 09:00 | 27 | [215] Gauthier Onclin v Rudolf Molleker [264] | 2-6,2-6 | |
Challenger - Amersfoort | 07/19 12:40 | 26 | Guy Den Ouden v Gauthier Onclin | 6-7,6-7 | |
Challenger - Amersfoort | 07/18 08:30 | 25 | [215] Gauthier Onclin v Oriol Roca Batalla [290] | 6-2,6-2 | |
Challenger - Iasi | 07/11 07:30 | 25 | Pablo Cuevas v Gauthier Onclin | 6-2,6-3 | |
Challenger - Milano | 07/07 10:00 | 27 | [115] Facundo D Acosta v Gauthier Onclin [216] | 6-4,6-3 | |
Challenger - Milano | 07/05 08:30 | 26 | [216] Gauthier Onclin v Alessandro Giannessi [241] | 6-4,6-1 | |
Challenger - Milano | 07/03 15:30 | 25 | [230] Edoardo Lavagno v Gauthier Onclin [216] | 6-1,3-6,4-6 |
Gauthier Onclin (born 26 February 2001) is a Belgian tennis player. He has a career high ranking of 194 achieved on September 18, 2023.
In January 2023 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 2023 he beat the higher-ranked Elias Ymer at a Challenger event in Bordeaux. 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 cancellation due to the COVID-19 pandemic.
In October 2023, 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 2024 Onclin reaches his first final in a Challenger tournament at the Prague Open. He loses to the former world number 35 Jiří Veselý.