The 26-year-old, ranked 435th in the world, did so against the odds with a surprise win over Chile’s 19-year-old Juan Lamadrid, ranked 74 places higher at 361.

He prevailed 11-9 in the deciding fifth game to secure a place in the main draw.

“I feel really good here; very comfortable, very positive." said Blas.

“Over the table, the short game, I felt confident.

"Also, if I played with a lot of spin I felt I could win."

Other men's singles group winners included Brazil's Vitor Ishiy and Humberto Manhani, Argentina's Rodrigo Gilabert and Horacio Cifuentes, Chile's Felipe Olivares and Venezuela's Marco Navas.

All of the leading names, including top-seeded Brazilian Hugo Calderano, will enter the fray on Saturday (December 6).

Venezuela's Neridee Niño produced the performance of the day on the women's side, with a 3-1 victory over higher-ranked Lady Ruano of Colombia followed by a straight-sets win over Mexico's Mercedes Madrid to secure first place in the group.

Puerto Rico's Brian Afanador beat Argentina’s Horacio Cifuentes 3-1, meanwhile, to set up an under 21 final with Alejandro Toranzos after the Paraguayan ousted Brazil's Vitory Ishiy in a five-set thriller.

It will be a family affair in the corresponding women's event as home sisters Adriana and Melanie Diaz each won their respective semi-finals.

Each was pushed to five-sets, with Melanie overcoming Chile’s Daniela Ortega before Adriana accounted for Uruguay’s Maria Pia Lorenzotti.

Both under 21 finals will take place tomorrow.