| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. S Alonso vs M Kazhgaleyev |
| 0-1 | 45 |
1999 |
Ubeda Open | B43 Sicilian, Kan, 5.Nc3 |
| 2. S Alonso vs P Ricardi |
| ½-½ | 24 |
1999 |
Malaga op 2nd | B90 Sicilian, Najdorf |
| 3. S Alonso vs S Slipak |
| 0-1 | 60 |
1999 |
XXX Mar del Plata International | B18 Caro-Kann, Classical |
| 4. F Braga vs S Alonso |
| ½-½ | 61 |
1999 |
10s, XXX op Mar del Plata ARG | B24 Sicilian, Closed |
| 5. S Alonso vs A Hoffman |
| 0-1 | 35 |
2000 |
Najdorf mem Great fin | C11 French |
| 6. J Sosa Harrison vs S Alonso |
| 1-0 | 34 |
2000 |
Najdorf mem Great fin | A36 English |
| 7. S Alonso vs J Sosa Harrison |
| 1-0 | 36 |
2000 |
Najdorf mem Great fin | B29 Sicilian, Nimzovich-Rubinstein |
| 8. A Hoffman vs S Alonso |
| ½-½ | 77 |
2000 |
Najdorf mem Great fin | A49 King's Indian, Fianchetto without c4 |
| 9. P Lafuente vs S Alonso |
| 1-0 | 46 |
2001 |
Boca Open | A15 English |
| 10. S Alonso vs S Cuesta Bustos |
| ½-½ | 43 |
2001 |
IV Open | B40 Sicilian |
| 11. S Alonso vs J M Pascual Perdiguero |
| 1-0 | 20 |
2001 |
5th Pablo Gorbea Mem Open | C11 French |
| 12. J Santana Martin vs S Alonso |
| 0-1 | 47 |
2001 |
IV Open | A45 Queen's Pawn Game |
| 13. C Dolezal vs S Alonso |
| ½-½ | 17 |
2001 |
Boca Open | B24 Sicilian, Closed |
| 14. M Ripari vs S Alonso |
| ½-½ | 27 |
2001 |
IV Open | B27 Sicilian |
| 15. S Alonso vs R Rubio Doblas |
 | 0-1 | 75 |
2001 |
IV Open | C84 Ruy Lopez, Closed |
| 16. S Alonso vs P Della Morte |
| 1-0 | 24 |
2001 |
Boca Open | B08 Pirc, Classical |
| 17. S Alonso vs F Terron Elena |
| 1-0 | 44 |
2001 |
IV Open | C96 Ruy Lopez, Closed |
| 18. M Diaz Begonte vs S Alonso |
| 0-1 | 25 |
2001 |
IV Open | A45 Queen's Pawn Game |
| 19. O Korneev vs S Alonso |
| 1-0 | 42 |
2001 |
XXVI Open | B45 Sicilian, Taimanov |
| 20. V Georgiev vs S Alonso |
| 1-0 | 54 |
2001 |
5th Pablo Gorbea Mem Open | B32 Sicilian |
| 21. N Cobo Prados vs S Alonso |
 | 0-1 | 51 |
2001 |
IV Open | B30 Sicilian |
| 22. S Alonso vs G Cativelli |
| 1-0 | 25 |
2001 |
Boca Open | B17 Caro-Kann, Steinitz Variation |
| 23. S Garcia Martinez vs S Alonso |
| 0-1 | 46 |
2001 |
IV Open | B62 Sicilian, Richter-Rauzer |
| 24. D Rivas Vila vs S Alonso |
| ½-½ | 22 |
2001 |
5th Pablo Gorbea Mem Open | B32 Sicilian |
| 25. S Alonso vs J Ridameya Tatche |
| ½-½ | 35 |
2001 |
IV Open | C47 Four Knights |