The 1966 Primera División was 36 . Playing time of the Argentine football league Primera División . The season began on March 6, 1966. The last game day was December 1, 1966. Colón de Santa Fe and Quilmes AC from the Primera B Nacional were promoted. The Racing Club finished the season as champions and became the successor to the Boca Juniors . Like the second-placed River Plate, they qualified for the Copa Libertadores in 1967 , which they also won - like the World Cup a little later against Manchester United . No teams had to relegate, as the league mode was completely restructured for the coming season and there were rounds (Torneo Metropolitano and Torneo Nacional) from 1967, with both six-month seasons producing an Argentine champion, so from 1967 there were two champions per year .