| ITF M25 Sao Paulo | 11/11 14:00 | 54 | Glauco Pinheiro Da Cruz Junior v Gabriel P Tumasonis | 4-6,6-1,10-6 | |
| ITF M15 Recife | 11/05 13:00 | 54 | Gabriel P Tumasonis v Enzo Lima | 2-6,3-6 | |
| ITF M25 Lajeado | 10/29 13:00 | 25 | Gabriel P Tumasonis v Joao Lucas Reis da Silva | 0-6,4-6 | |
| ITF M25 Lajeado | 10/28 16:00 | 54 | Laelson Rodrigues v Gabriel P Tumasonis | 4-6,4-6 | |
| ITF M25 Belem | 08/22 19:00 | 26 | Gabriel P Tumasonis v Juan C P Angelo | 6-7,1-6 | |
| ITF M25 Belem | 08/21 01:45 | 25 | Gabriel P Tumasonis v Eduardo Lima | 6-1,6-1 | |
| ITF M25 Belem | 08/19 15:15 | 54 | Gabriel P Tumasonis v Julian Cundom | Retired | |
| ITF M25 Belem | 08/18 16:00 | 54 | Gabriel P Tumasonis v Breno Braga | 6-0,6-4 | |
| ITF M25 Londrina | 08/12 16:00 | 54 | Valentin Garay v Gabriel Tumasonis | 6-0,6-3 | |
| ITF M25 Londrina | 08/11 13:00 | 54 | Antonio Neris v Gabriel P Tumasonis | 2-6,0-6 | |
| ITF M25 Sao Paulo | 07/10 19:45 | 25 | Gabriel P Tumasonis v Mateo Barreiros Reyes | 2-6,3-6 | |
| ITF M25 Sao Paulo | 07/09 13:00 | 54 | Gabriel P Tumasonis v Matheus C Bueres | 4-6,7-6,10-6 | |
| ITF M25 Sao Paulo | 07/08 17:35 | 54 | Jefferson Wendler Filho v Gabriel P Tumasonis | 4-6,3-6 | |
| ITF M15 Belem | 07/01 23:00 | 54 | Gabriel P Tumasonis v Raul De La Vega | 4-6,6-0,8-10 | |
| ITF M25 Maceio | 03/21 01:25 | 25 | Mateus Alves v Gabriel P Tumasonis | 6-1,6-2 | |
| ITF M25 Maceio | 03/18 15:00 | 54 | Facundo Bermejo v Gabriel P Tumasonis | 5-7,2-6 | |
| ITF M25 Feira De Santana | 03/10 13:00 | 54 | Joaquim Almeida v Gabriel P Tumasonis | Retired | |
| ITF M25 Recife | 03/06 14:40 | 25 | Gabriel P Tumasonis v Quentin Folliot | 4-6,6-4,4-6 | |
| ITF M25 Recife | 03/04 15:15 | 54 | Facundo Bermejo v Gabriel P Tumasonis | 0-6,6-7 | |
| ITF M25 Recife | 03/03 16:00 | 54 | Guilherme Meale v Gabriel P Tumasonis | 0-6,2-6 | |
| Challenger Piracicaba | 01/28 18:45 | 14 | Damien Wenger v Gabriel Tumasonis | 6-1,6-1 | |
| ITF M25 Lajeado | 10/09 16:00 | 54 | Sean Hess v Gabriel P Tumasonis | 6-3,6-2 | |
| ITF M15 Sao Paulo | 08/21 16:30 | 54 | Enzo Lima v Gabriel P Tumasonis | 6-3,6-1 | |
| ITF M15 Belem | 08/15 13:00 | 54 | Gabriel P Tumasonis v Miguel Angel Cabrera | 0-6,1-6 | |
| ITF M15 Belem | 08/14 13:00 | 54 | Gabriel P Tumasonis v Valentin M Greco | 6-3,6-3 | |
| ITF M25 Mosquera | 03/20 18:40 | 54 | Arvid Nordquist v Gabriel P Tumasonis | 6-3,6-4 | |
| ITF M25 Anapoima | 03/12 15:00 | 54 | Joel Angel Lucero v Gabriel P Tumasonis | 6-1,6-2 | |
| ITF M25 Santo Domingo | 02/20 14:00 | 62 | Ziwen Ju v Gabriel P Tumasonis | 7-6,6-3 | |
| ITF M25 Santo Domingo Qual | 02/19 13:00 | 62 | Liam Oliver v Gabriel P Tumasonis | 6-3,4-6,6-10 | |
| ITF M25 Santo Domingo | 02/14 13:00 | 62 | Gabriel P Tumasonis v Thomas Brown | 3-6,1-6 |