Challenger de Nonthaburi | 01/16 07:00 | 25 | [218] Gauthier Onclin v Clement Tabur [233] | 6-4,6-3 | |
Open de Australia | 01/10 05:15 | 14 | [103] Aleksandar Kovacevic v Gauthier Onclin [220] | 6-3,6-7,7-6 | |
Challenger de Nonthaburi | 01/04 03:30 | 27 | [231] Gauthier Onclin v Lucas Pouille [329] | 3-6,2-6 | |
Challenger de Nonthaburi | 01/03 03:00 | 26 | [251] Evgeny Donskoy v Gauthier Onclin [231] | 3-6,3-6 | |
Challenger de Nonthaburi | 01/01 08:45 | 25 | [231] Gauthier Onclin v Yasutaka Uchiyama [269] | 7-5,6-2 | |
Challenger de Danderyd | 11/16 09:00 | 26 | Gauthier Onclin v Flavio Cobolli | Walkover | |
Challenger de Danderyd | 11/14 17:15 | 25 | [380] Leo Borg v Gauthier Onclin [227] | 6-2,4-6,0-6 | |
Challenger de Helsinki | 11/06 13:35 | 19 | [228] Gauthier Onclin v Maximilian Neuchrist [258] | 5-7,4-6 | |
Challenger de Helsinki | 11/05 10:30 | 14 | Gauthier Onclin v Markus Molder | 6-0,6-4 | |
Challenger de Bérgamo | 10/31 09:00 | 25 | [216] Gauthier Onclin v Radu Albot [132] | 7-6,0-6,0-6 | |
Challenger de Ortisei | 10/23 15:25 | 25 | [310] Maks Kasnikowski v Gauthier Onclin [216] | 6-1,6-4 | |
ATP Amberes | 10/16 09:30 | 19 | [214] Gauthier Onclin v Giovanni M Perricard [226] | 4-6,2-6 | |
ATP Amberes | 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 de Estambul | 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 de Meerbusch | 08/10 15:30 | 26 | [203] Gauthier Onclin v Max Hans Rehberg [413] | 6-7,6-7 | |
Challenger de Meerbusch | 08/08 13:05 | 25 | [203] Gauthier Onclin v Gerard Campana Lee [419] | 2-6,7-5,6-1 | |
Challenger de Luedenscheid | 08/04 12:00 | 27 | [208] Gauthier Onclin v Benoit Paire [126] | 4-6,4-6 | |
Challenger de Luedenscheid | 08/03 14:00 | 26 | [208] Gauthier Onclin v Santiago Rodriguez Taverna [272] | 6-1,6-4 | |
Challenger de Luedenscheid | 08/01 15:40 | 25 | [148] Jan Choinski v Gauthier Onclin [208] | 4-6,2-6 | |
Challenger de Amersfoort | 07/21 09:00 | 27 | [215] Gauthier Onclin v Rudolf Molleker [264] | 2-6,2-6 | |
Challenger de Amersfoort | 07/19 12:40 | 26 | Guy Den Ouden v Gauthier Onclin | 6-7,6-7 | |
Challenger de Amersfoort | 07/18 08:30 | 25 | [215] Gauthier Onclin v Oriol Roca Batalla [290] | 6-2,6-2 | |
Challenger de Iasi | 07/11 07:30 | 25 | Pablo Cuevas v Gauthier Onclin | 6-2,6-3 | |
Challenger de Milán | 07/07 10:00 | 27 | [115] Facundo D Acosta v Gauthier Onclin [216] | 6-4,6-3 | |
Challenger de Milán | 07/05 08:30 | 26 | [216] Gauthier Onclin v Alessandro Giannessi [241] | 6-4,6-1 | |
Challenger de Milán | 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 184 achieved on September 18, 2023.
In January 2023 Onclin reached the semifinals of the 2023 BW Open in Mons 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.