Nicknamed "Chango", he played as a forward primarily during the 1970s; he was a part of football clubs such as Rosario Central, Panathinaikos and Huracán.

He also briefly played for Argentina to be listed in the Brazil Independence Cup roster, despite not traveling with the team.

He made his debut within the Argentine Primera División at the 1967 Campeonato Nacional against Platense in a 3–0 victory at the Estadio Marcelo Bielsa.

As in his prior match, Gramajo would be the substitute for Enzo Gennoni [es], who had been removed from the starting line-up.

Another match he would remember from the season was the annual Rosario derby against Newell's Old Boys, in which Central would win 4–1 at the Estadio Marcelo Bielsa.

During the Metropolitano Championship on 22 August 1971, he would observe the 2–1 defeat against Racing, taking note of movements and the penalty kick of Juan Carlos Cárdenas after the two goalkeepers were expelled from the match.

Afterwards, Gramajo executed 14 penalties while with Rosario Central, of which he converted 10; two were detoured, while another two were stopped in a scenario similar to that of the one occurring with Miguel Ángel Santoro during the 1970 Campeonato Nacional.

He also played in sixteen Rosario Derbies and lost one of them, with the rest of the games resulting in five wins and ten draws.

Gramajo played alongside players such as Norberto Madurga, Roberto Perfumo, Juan Ramón Verón, Jorge Carrascosa, Alfredo Obberti.