| ITF M25 Campos do Jordao | 01/31 14:00 | 54 | Gabriel P Tumasonis v Drew Van Orderlain | 7-6,6-3 | |
| Challenger Blumenau | 01/10 18:05 | 19 | Jose Pereira v Gabriel Tumasonis | 6-2,6-3 | |
| Challenger Blumenau | 01/09 15:45 | 14 | Gabriel Tumasonis v Alec Deckers | 4-6,6-2,6-4 | |
| Challenger Rio De Janeiro | 12/12 18:00 | 14 | Gabriel Tumasonis v Rafael Matos | 3-6,5-7 | |
| ITF M15 Brasilia | 11/04 13:00 | 26 | Eduardo Ribeiro v Gabriel P Tumasonis | 6-2,6-1 | |
| ITF M15 Brasilia | 11/03 12:00 | 25 | Lucas Obeid v Gabriel P Tumasonis | 2-6,1-6 | |
| ITF M15 Brasilia | 11/03 12:00 | 25 | Natan Rodrigues v Gabriel P Tumasonis | Cancelled | |
| ITF M15 Brasilia | 11/02 12:00 | 54 | Gabriel P Tumasonis v Eduardo Lacalle | 6-3,4-6,11-9 | |
| ITF M15 Brasilia | 11/01 12:00 | 54 | Sean Hess v Gabriel P Tumasonis | 1-6,6-4,8-10 | |
| ITF M25 Rio do Sul | 10/18 20:10 | 54 | Pedro Cressoni v Gabriel P Tumasonis | 7-5,6-4 | |
| ITF M15 Recife | 09/22 17:00 | 25 | Gabriel P Tumasonis v Asdrubal Gobernate | 2-6,3-6 | |
| ITF M15 Recife | 09/20 13:00 | 54 | Victor Bertoldo v Gabriel P Tumasonis | 3-6,3-6 | |
| ITF M15 Sao Paulo | 10/14 14:00 | 54 | Andre Miele v Gabriel P Tumasonis | 6-0,6-2 | |
| ITF Brazil F9 | 11/13 13:20 | 25 | Rafael Matos v Gabriel P Tumasonis | 7-6,6-1 | |
| ITF Brazil F9 | 11/12 13:35 | 44 | Gabriel P Tumasonis v Lucas Bernardo | 6-4,6-1 | |
| ITF Brazil F8 | 11/04 15:30 | 44 | Gabriel P Tumasonis v Joao Hinsching | 4-6,2-6 | |
| ITF Brazil F8 | 11/03 16:30 | 44 | Gabriel P Tumasonis v Hugo Moura | 6-2,6-4 | |
| ITF Brazil F7 | 10/27 14:30 | 62 | Pedro Gabriel Rodrigues v Gabriel P Tumasonis | 6-1,6-0 | |
| ITF Brazil F6 | 10/20 15:30 | 44 | Gabriel P Tumasonis v Karl W W Mac-Leay | 3-6,3-6 | |
| ITF Brazil F5 | 10/15 14:00 | 44 | Joao Hinsching v Gabriel P Tumasonis | 6-0,6-2 | |
| ITF Brazil F5 | 10/14 13:00 | 44 | Victor Bertoldo v Gabriel P Tumasonis | 1-6,0-6 | |
| ITF Spain F29 | 09/23 07:00 | 62 | Gabriel P Tumasonis v Max Alcala Gurri | 1-6,3-6 | |
| ITF Spain F28 Qual | 09/16 12:00 | 62 | Gabriel P Tumasonis v Sergio Barranco | 4-6,6-4,6-7 | |
| ITF Spain F28 Qual | 09/15 14:00 | 62 | Gabriel P Tumasonis v Carlos Fernandez-Espinar | 6-3,6-3 | |
| ITF Spain F27 | 09/09 08:45 | 62 | Ivan Marrero Curbelo v Gabriel P Tumasonis | 6-4,6-0 | |
| ITF Spain F27 | 09/08 10:30 | 62 | Gabriel P Tumasonis v Angel G Melgar | 6-1,6-3 | |
| ITF Spain F26 | 09/01 08:00 | 54 | Luis D C Villalpando v Gabriel P Tumasonis | 6-3,7-6 | |
| ITF Portugal F16 | 08/19 08:30 | 62 | Gabriel P Tumasonis v Goncalo Falcao | 5-7,3-6 | |
| ITF Portugal F16 | 08/18 08:30 | 62 | Dario Montes v Gabriel P Tumasonis | 4-6,5-7 | |
| ITF Portugal F15 | 08/11 08:30 | 62 | Gabriel P Tumasonis v Miguel Semedo | 5-7,1-6 |