| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. F Casas vs A Foguelman |
| ½-½ | 46 | 1958 | Mar del Plata | E32 Nimzo-Indian, Classical |
| 27. Panno vs F Casas |
| 1-0 | 50 | 1958 | Mar del Plata | D57 Queen's Gambit Declined, Lasker Defense |
| 28. F Casas vs J Pelikan |
| 1-0 | 19 | 1958 | Mar del Plata | B32 Sicilian |
| 29. J Emma vs F Casas |
| ½-½ | 41 | 1958 | Mar del Plata | A07 King's Indian Attack |
| 30. F Casas vs A Olivera |
| ½-½ | 33 | 1958 | Mar del Plata | E45 Nimzo-Indian, 4.e3, Bronstein (Byrne) Variation |
| 31. R Sanguineti vs F Casas |
| 1-0 | 47 | 1958 | Mar del Plata | B39 Sicilian, Accelerated Fianchetto, Breyer Variation |
| 32. F Casas vs E Reinhardt |
| 1-0 | 36 | 1958 | Mar del Plata | E36 Nimzo-Indian, Classical |
| 33. Lombardy vs F Casas |
| 1-0 | 44 | 1958 | Mar del Plata | A05 Reti Opening |
| 34. F Casas vs Letelier |
| 0-1 | 57 | 1958 | Mar del Plata | D52 Queen's Gambit Declined |
| 35. F Casas vs J Behrensen |
| ½-½ | 56 | 1958 | Mar del Plata | B28 Sicilian, O'Kelly Variation |
| 36. Eliskases vs F Casas |
| ½-½ | 22 | 1958 | Mar del Plata | A70 Benoni, Classical with 7.Nf3 |
| 37. F Casas vs Eliskases |
| 0-1 | 35 | 1959 | ARG | E81 King's Indian, Samisch |
| 38. M A Casabella vs F Casas |
| ½-½ | 42 | 1960 | Santa Fe | D95 Grunfeld |
| 39. F Casas vs H Rossetto |
| 1-0 | 39 | 1960 | Santa Fe | C79 Ruy Lopez, Steinitz Defense Deferred |
| 40. F Casas vs Gligoric |
 | 0-1 | 33 | 1960 | Santa Fe | D72 Neo-Grunfeld, 5.cd, Main line |
| 41. Taimanov vs F Casas |
| 1-0 | 26 | 1960 | Santa Fe | A71 Benoni, Classical, 8.Bg5 |
| 42. F Casas vs Szabo |
| ½-½ | 86 | 1960 | Santa Fe | A53 Old Indian |
| 43. F Casas vs Korchnoi |
| ½-½ | 42 | 1960 | Santa Fe | D91 Grunfeld, 5.Bg5 |
| 44. J Klein vs F Casas |
| 1-0 | 38 | 1960 | Santa Fe | A87 Dutch, Leningrad, Main Variation |
| 45. F Casas vs A Foguelman |
| 1-0 | 49 | 1961 | ARG-ch | D91 Grunfeld, 5.Bg5 |
| 46. F Casas vs O Bazan |
| 0-1 | 43 | 1961 | ARG-ch | A02 Bird's Opening |
| 47. F Casas vs R Garcia |
| 1-0 | 34 | 1963 | Buenos Aires Circulo Argentino | A69 Benoni, Four Pawns Attack, Main line |
| 48. F Casas vs S Schweber |
| 1-0 | 68 | 1963 | Buenos Aires Circulo Argentino | E38 Nimzo-Indian, Classical, 4...c5 |
| 49. B Marcussi vs F Casas |
| 0-1 | 24 | 1963 | Buenos Aires Circulo Argentino | B48 Sicilian, Taimanov Variation |
| 50. F Casas vs R C Cruz |
| ½-½ | 32 | 1963 | Buenos Aires Circulo Argentino | E92 King's Indian |
Kibitzing
