| WTT Contender - Doha | 03/19 08:45 | - | Mehdi Bouloussa v Monteiro, Thiago | L | 3-0 | |
| WTT Feeder Doha | 03/15 17:25 | - | Enzo Angles v Monteiro, Thiago | L | 4-1 | |
| WTT Feeder Doha | 03/15 10:50 | - | Snehit Suravajjula v Monteiro, Thiago | L | 3-2 | |
| WTT Singapore Smash | 03/08 03:45 | - | Marcos Madrid v Monteiro, Thiago | L | 3-1 | |
| World Championship | 11/25 00:00 | 57 | Jonathan Groth v Monteiro, Thiago | L | 4-0 | |
| World Championship | 11/23 18:20 | 57 | Nikhil Kumar v Monteiro, Thiago | W | 3-4 | |
| WTT Contender Lasko | 11/04 17:40 | - | Monteiro, Thiago v Quadri Aruna | L | 1-3 | |
| Ligue des Champions | 09/17 13:50 | - | Demeter, Lehel v Monteiro, Thiago | L | 3-1 | |
| Ligue des Champions | 09/17 12:30 | - | Zsolt Peto v Monteiro, Thiago | W | 2-3 | |
| Ligue des Champions | 09/16 13:50 | - | Monteiro, Thiago v Sidorenko, Vladimir | - | Cancelled | |
| Ligue des Champions | 09/16 12:30 | - | Monteiro, Thiago v Kay Stumper | L | 0-3 | |
| Ligue des Champions | 09/15 18:50 | - | Monteiro, Thiago v Andreas Levenko | L | 1-3 | |
| Ligue des Champions | 09/15 17:35 | - | Monteiro, Thiago v Nandor Ecseki | W | 3-2 | |
| WTT Star Contender Doha | 03/07 12:50 | - | Dang Qiu v Monteiro, Thiago | L | 3-1 | |
| WTT Star Contender Doha | 03/07 08:10 | - | Karakasevic, Aleksandar v Monteiro, Thiago | W | 1-3 | |
| WTT Star Contender Doha | 03/06 15:00 | - | Monteiro, Thiago v Anders Lind | W | 3-2 | |
| WTT Contender - Doha | 02/28 09:56 | - | Joao Geraldo v Monteiro, Thiago | L | 3-0 | |
| Ligue des Champions | 12/15 16:50 | - | Kristian Karlsson v Monteiro, Thiago | W | 2-3 | |
| Ligue des Champions | 12/13 09:20 | - | Felipe Olivares v Monteiro, Thiago | W | 1-3 | |
| Ligue des Champions | 12/12 09:20 | - | Monteiro, Thiago v Liam Pitchford | L | 2-3 | |
| Challenge Plus Oman Open 2020, MS | 03/13 14:20 | 5 | Aliaksandr Khanin v Monteiro, Thiago | L | 4-1 | |
| Qatar Open 2020, MS, Qualification | 03/04 09:30 | - | Monteiro, Thiago v Anders Lind | L | 0-4 | |
| Challenge Plus Portugal Open 2020, MS, Quali | 02/14 14:05 | 6 | Yi-Hsin Feng v Monteiro, Thiago | L | 4-1 | |
| ITTF Challenge, Spanish Open 2020, MS | 02/06 14:00 | 6 | Monteiro, Thiago v Carlos Caballero | L | 2-4 | |
| German Open 2020, MS | 01/28 16:35 | - | Monteiro, Thiago v Kai Zhang | L | 2-4 | |
| North American Open | 12/07 00:50 | - | Monteiro, Thiago v Xu, Haidong | L | 3-4 | |
| North American Open | 12/06 20:15 | - | Monteiro, Thiago v Vilchez, Miguel | W | 4-2 | |
| Austrian Open 2019, MS | 11/13 12:30 | - | Maharu Yoshimura v Monteiro, Thiago | L | 4-2 | |
| Polish Open | 10/19 17:30 | - | Xu, Haidong v Monteiro, Thiago | L | 4-0 | |
| Polish Open | 10/19 12:20 | - | Kakeru Sone v Monteiro, Thiago | W | 0-4 |