| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. N Lokesh vs X Mastalerz |
| ½-½ | 38 |
2011 |
World Junior Championships | C02 French, Advance |
| 2. G Botta vs X Mastalerz |
| 1-0 | 33 |
2011 |
World Junior Championships | C05 French, Tarrasch |
| 3. X Mastalerz vs K R A Pradeep |
| 0-1 | 59 |
2011 |
World Junior Championships | B33 Sicilian |
| 4. X Mastalerz vs J Benitez Lozano |
| ½-½ | 51 |
2011 |
World Junior Championships | A46 Queen's Pawn Game |
| 5. X Mastalerz vs K Abhishek |
| 0-1 | 54 |
2011 |
World Junior Championships | A50 Queen's Pawn Game |
| 6. H Sharma vs X Mastalerz |
| ½-½ | 21 |
2011 |
World Junior Championships | C11 French |
| 7. H Santos vs X Mastalerz |
| ½-½ | 28 |
2011 |
World Junior Championships | C00 French Defense |
| 8. Z Tomazini vs X Mastalerz |
| 1-0 | 37 |
2011 |
World Junior Championships | C02 French, Advance |
| 9. X Mastalerz vs J Arun |
| 1-0 | 25 |
2011 |
World Junior Championships | E06 Catalan, Closed, 5.Nf3 |
| 10. X Mastalerz vs J Yohan |
| 1-0 | 29 |
2011 |
World Junior Championships | D05 Queen's Pawn Game |
| 11. X Mastalerz vs A M Petrisor |
| 0-1 | 50 |
2011 |
World Junior Championships | A37 English, Symmetrical |
| 12. E Kozganbayev vs X Mastalerz |
| 1-0 | 42 |
2011 |
World Junior Championships | A28 English |
| 13. N R Visakh vs X Mastalerz |
| 0-1 | 32 |
2011 |
World Junior Championships | A07 King's Indian Attack |
| 14. A Fransson vs X Mastalerz |
| 0-1 | 40 |
2012 |
Tradewise Gibraltar | C00 French Defense |
| 15. X Mastalerz vs J Vojinovic |
| ½-½ | 37 |
2012 |
Tradewise Gibraltar | E94 King's Indian, Orthodox |
| 16. X Mastalerz vs S Phadke |
| 0-1 | 29 |
2012 |
Tradewise Gibraltar | D32 Queen's Gambit Declined, Tarrasch |
| 17. X Mastalerz vs G Quillan |
| ½-½ | 30 |
2012 |
Tradewise Gibraltar | C16 French, Winawer |
| 18. S Marano vs X Mastalerz |
| 0-1 | 30 |
2012 |
Tradewise Gibraltar | C00 French Defense |
| 19. T Coleman vs X Mastalerz |
| ½-½ | 50 |
2012 |
Tradewise Gibraltar | E25 Nimzo-Indian, Samisch |
| 20. X Mastalerz vs R Montero Melendez |
| 0-1 | 45 |
2012 |
Tradewise Gibraltar | E15 Queen's Indian |
| 21. X Mastalerz vs C Nwachukwu |
| 1-0 | 52 |
2012 |
Tradewise Gibraltar | D91 Grunfeld, 5.Bg5 |
| 22. A Cabrera vs X Mastalerz |
| 1-0 | 26 |
2012 |
Tradewise Gibraltar | E32 Nimzo-Indian, Classical |