| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 26. M Erwich vs L D'Costa |
| 1-0 | 55 |
2001 |
Glorney Cup | B73 Sicilian, Dragon, Classical |
| 27. L D'Costa vs C Hanley |
| ½-½ | 19 |
2001 |
Smith & Williamson ch-GBR | A10 English |
| 28. L D'Costa vs B Kelly |
| ½-½ | 18 |
2001 |
Smith & Williamson ch-GBR | D43 Queen's Gambit Declined Semi-Slav |
| 29. L D'Costa vs J Werle |
| 0-1 | 38 |
2001 |
EYCC B18 | A15 English |
| 30. L D'Costa vs M Quinn |
| 1-0 | 34 |
2002 |
4NCL/Div1/BAR2 vs. RIC | E11 Bogo-Indian Defense |
| 31. D Gormally vs L D'Costa |
| 1-0 | 47 |
2002 |
British Chess Championships | D85 Grunfeld |
| 32. L D'Costa vs Emms |
| ½-½ | 14 |
2002 |
British Chess Championships | E14 Queen's Indian |
| 33. L D'Costa vs P Wells |
| 0-1 | 26 |
2002 |
BCF-chT 0203 (4NCL) | D44 Queen's Gambit Declined Semi-Slav |
| 34. A Kunte vs L D'Costa |
| 1-0 | 27 |
2002 |
British Chess Championships | D78 Neo-Grunfeld, 6.O-O c6 |
| 35. L D'Costa vs Flear |
| ½-½ | 72 |
2002 |
British Chess Championships | D45 Queen's Gambit Declined Semi-Slav |
| 36. L D'Costa vs M Harborne |
| 1-0 | 34 |
2002 |
British Chess Championships | E14 Queen's Indian |
| 37. Ganguly vs L D'Costa |
| ½-½ | 103 |
2002 |
British Chess Championships | B74 Sicilian, Dragon, Classical |
| 38. L D'Costa vs A J Mestel |
| ½-½ | 66 |
2003 |
BCF-chT 0304 (4NCL) | A64 Benoni, Fianchetto, 11...Re8 |
| 39. L D'Costa vs R Almond |
| 1-0 | 38 |
2003 |
Hastings Challengers 0304 | D35 Queen's Gambit Declined |
| 40. L D'Costa vs G Kuzmin |
| ½-½ | 60 |
2003 |
Hastings Challengers 0304 | E11 Bogo-Indian Defense |
| 41. L D'Costa vs J Vogel |
| 1-0 | 39 |
2004 |
Amsterdam ACT op 1st | E12 Queen's Indian |
| 42. L D'Costa vs Srinivas Sai |
| 1-0 | 33 |
2004 |
Wch U20 | D91 Grunfeld, 5.Bg5 |
| 43. L D'Costa vs F Van der Elburg |
| ½-½ | 63 |
2004 |
Amsterdam ACT op 1st | A88 Dutch, Leningrad, Main Variation with c6 |
| 44. L D'Costa vs A Das |
| ½-½ | 15 |
2004 |
Wch U20 | E12 Queen's Indian |
| 45. L D'Costa vs F Mandiza |
| 1-0 | 45 |
2004 |
Wch U20 | B03 Alekhine's Defense |
| 46. L D'Costa vs Stellwagen |
| 0-1 | 35 |
2004 |
Amsterdam ACT op 1st | A64 Benoni, Fianchetto, 11...Re8 |
| 47. L D'Costa vs C Vaidya |
| ½-½ | 38 |
2004 |
Wch U20 | C05 French, Tarrasch |
| 48. L D'Costa vs Y Sandeep |
| 1-0 | 39 |
2004 |
Wch U20 | D85 Grunfeld |
| 49. L D'Costa vs G N Gopal |
| 1-0 | 45 |
2004 |
Wch U20 | D85 Grunfeld |
| 50. L D'Costa vs E L'Ami |
| 0-1 | 54 |
2004 |
Amsterdam ACT op 1st | D94 Grunfeld |