RIO DE JANEIRO, Dec 20 (Reuters) - Vasco da Gama got a vital three points in their battle against relegation on Sunday when a goal from Carlinhos gave them a 1-0 win over Santos in Brazil's Serie A.The midfielder volleyed home a cross at the far post after eight minutes to score the only goal of the game.It was Vasco's first win in six league matches and only their second in 16.The Rio de Janeiro club remain fourth bottom in the final relegation spot but they now have 28 points and are just five points away from the top half of the 20-team table.Santos are in eighth, with 36 points. (Reporting by Andrew Downie Editing by Christian Radnedge)